Go Big or Go home is damn near impossible on a large map. I did it on Point Blank. Pick TEC and send a Marza over to your enemie's homeworld. It can get his constructors and take on your opponent's cap early. What you must do is not upgrade your homeworld, and instead, invest your early resources in a second cap. Say, a Kol or an Akkan. What this does is it alows you to destory your computer opponent early.

This task is frankly a little ridiculous. Only Capital ship fleets lose damn quick.

I've effectively done this against a Hard Aggressive AI on Point Blank, as TEC. The thing you need to capitalize on is that the AI, while hard and aggressive, doesn't really adapt the way that a human player would.

The best way to do this on this map is to just be offensive, and not worry about colonizing other things.

Point Blank starts you on a desert planet, so you can't upgrade your planet population. So, for the cap-ship build, you should start out by scuttling your frigate factory, building the cap factory, all available extractors, and a military research station.

The first capital ship you need is the Kol battlecruiser, since it can take a good amount of punishment. In the first few minutes of the game, you'll have to play defensively and buy for time, because the enemy is gonna fly in their own cap ship and about 6-7 frigates, while all you have is the one cap ship. Giving the Kol the experimental shields ability is your best bet for success here.

Now, to get that second cap ship out, all you need to do is the one Command Crew research. Your starting fleet size is actually enough to accommodate two cap ships.

Once you have the cash, I'd suggest building a Dunov support cruiser. Its Recharge Shields ability is invaluable here. By the time it comes out, your Kol has probably lost all shields and taken a bit of hull damage, but having the Dunov there for support will help you destroy the enemy fleet (or at the very least, have them retreat).

At this point, since you have a military research structure, you should research repair bays, and build a few on your planet. Then, fly your two cap ships to the enemy home planet. Make sure the Kol is in the front - most if not all of the AIs ships will target it, leaving the Dunov to sit in the back and just keep recharging its shields (this is what I was talking about with taking advantage of the AI - a human player would more intelligently go straight for the Dunov). Stay in the planet and do as much damage as possible, but once you start losing the fight, retreat back to your own planet and its repair bays. Just keep doing this over and over again ... you'll probably need upwards of 4 cap ships eventually (I favor having the 3rd ship be a 2nd Dunov, and the 4th be a Marza) before you turn the tide and overrun them.

Of course, be getting relevant military upgrades all the while, and your ships will most likely all get to level 4 by the time all is said and done.

I haven't had much success with other races ... The Kol/Dunov combination seems to be the best bet to win this achievement.

This is interesting because from what I remember (not looking at it now) to get the achievement you had to use all of the cap ship slots. Is this not the case? From what I am reading it looks like it isn't. If not, I would imagine it would be a lot easier because you could "rush" with caps early and throw the AI off. I was playing rather defensively and keeping only a few planets to not stretch myself too thin but it was too difficult.

It does appear that I need to keep this against 1 opponent.

Is TEC the only one to do this with? I haven't really played them, most just Vasari. Maybe it's time to expand into other races then expand out and do this.

There are three achievements having to do with capital ships:
1) Beat the game without using cruisers, frigates or strike aircraft (thus it is necessary to use capital ships)
2) Own at least 1 capital ship of every kind at the same time (there is a separate achievement for each race to do this, I think)
3) Own the maximum amount of capital ships at the same time, while also having all fleet researches completed.

yup, quite easy

I recall doing this on Doppelgangers as Advent and Fulcrum as TEC.

As Advent it was simply a matter of pairing Progenitor Motherships with Radiance Battlecruisers. After I had 2 or 3 of each kind I'd start building other capital ships. I'd always make sure the Radiance would spearhead assaults so the AI would target it first, thus leaving the Progenitor to do repairs each time while also attacking. I also had heavy defenses during that game. I'd also always micromanage the targeting on the Progenitors so that they were in the thick of battle with all banks firing on something. This is probably much harder to do these days since they nerfed Malice so badly. The more capital ships I got, the easier my time was. Fleets of 5 to 8 capital ships worked well for the fleets. I didn't have much success with small strike groups of 3 capital ships unless the planet was not defended by enemy ships. My advance as Advent was slow and steady without a retreat. As enemy forces grew, so did my capital ships. I also remember racing to the top of the military tech tree to get the auto-leveling up for capital ships ASAP. I also spent a little on the economy.

When I was TEC, I immediately sent a Sova Carrier to the enemy homeworld and started siphoning credits and causing chaos. I would hit the smaller ships first so that the Sova would gain experience and start dropping missile pods off to help in the battle. By the time the Sova had to retreat I had a Kol there to cover its departure. Then I'd have the Sova come back, sit on the outskirts and let its long range weapons and strike craft do damage. The Kol and Sova normally were sufficient to stop offensive enemy forces at the home world, although I had to micromanage things to prevent construction facilities from being built. I'd be building a Dunov next and using it for defense or sending it to wipe out one AI's home world. The next capital ship would be another Sova or Kol. I recall having to pair a Dunov and Kol together as well as pair together the Sova and other Kol because I was getting attacked on 2 fronts. At that point it was a pretty defensive battle to save resources, until a fifth capital ship became available. I grouped a trio of capital ships into a fleet and took them offensive, commonly retreating after doing lots of damage to the enemy. I'd try to make the two fleets flank an enemy target as much as possible until 8 capital ships became available. By that time the Kols had gotten so high in level that they were unstoppable as long as I took care of them. As for research here, I did a little of military and a little of economics. Most money was gained off embargo even if I sent a Sova into a system only to have it chased off shortly after arrival--it was still free money.

Think on your toes and consider the above. If you micromanage things to make sure your ships are firing on all banks, then you'll have an easier time. I know I'd purposely put capital ships right into the middle of a battle and order them to retreat only when their HP got to 1,500 for a small enemy force or 2,200 for a large enemy force. The presence of phase jump inhibitors necessitated a build up for allied forces since the PJI would be the primary target after having jumped in. Also prioritize capital ships that can heal when choosing targets.

I did my "Go big or go home" with the TEC on "Systems of War" (4 players, 5 systems), and did a 2x2 with pirates enabled. So I did have frigates - my ally's, and the pirates . Normal difficulty only... I regard special restrictions to be an inherent "hard" setting, and see no need to bump it up further.

Key to this is to realize that capships are SLOW. Therefore you have to figure out where you need to be well in advance of being there. If you get attacked in a system and you don't have a cap nearby, give up on that system, build fortifications on the nearby ones, and task a force with an Akkan to throw back the assault and retake the worlds.

The capship slowness also means, paradoxically, that you have to outexpand the AI at first in order to be competitive later. You need to begin with 2 Akkans and take as many worlds as possible before the AI catches up. I had begun on the central system before the AI finished their home systems (note that on hard, the AI will outexpand and eventually kill you). Your need for cash and hence trade is critical: you must purchase capship upgrades and ensure your enemies are too preoccupied with pirate raids to hinder your desperate expansion. That also means that contra the first commenter's advice, you MUST upgrade homeworld immediately like normal. Otherwise you get the second cap earlier but you can't pay for upgrades.

Then I built the following order of capships:
Kol, Dunov, Kol, Kol, Dunov, Kol, Dunov, Sova, Mazra, the rest Kol's.

I probably shouldn't have built 3 Dunov's - You fight on 2 fronts often, 3 not so much. Once you get a Dunov/Sova/Mazra combo, its time to harass the enemy with it. Eventually add an Akkan and maybe a Kol and the will mop up worlds. 2 Kols and one Dunov can handle medium-size threats, and 1-2 Kols should play defender at each of your star systems.

Capships are not enough firepower to fight off the enemy: You also need fixed defenses. Fortuately, you are playing against normal AI, so they can be relied on to mostly attack the nearest planets. At each heavily contested world, you eventually want four hangers, 1 pji, 2 repair bays healing each other, and one turret to fight off close-range attacks. This will hold the world until the patrolling capship(s) can help. This combo, if all-bombers, can survive a max-pirate assault with only nominal capship help.

Key abilities:
* Shield restore: any time you face a major attack, this Dunov ability will keep the Kol(s) going forever.
* Targetting uplink: Because you need every shot to count, and what else are you going to spend the point on?
* Flux field: Turn this on then set all Kol's to spam railgun shots and flak while recharging with...
* Finest hour. The only way you are going to get the firepower you need to kill enemy fleets. Remember to get the Kol right in the middle of the enemy formation to use all guns.
* Embargo - no reinforcements for you! Give me some money for upgrades!
* Radiation bomb, EMP charge: Any attack that affects multiple ships is something you NEED. Now. Because you will always be outnumbered, and every shot that isn't killing hull is a wasted shot.
* Armistice: Suspends the battle until the Kol(s) arrive or if you need just a little more time to install those tatical buildings.

One part I forgot - after you have the computer players reasonably under control and take the closest planets to the pirates, build them up with defenses then have the pirates attack you to build up the levels of the capships you have defending that star system. This will help you go for the "captain" bonus where you max out one capship's level.

If the computer players are about to die and you haven't achieved all the achievments you want, backstab your AI ally before he kills them off. Then you can go for all kinds of achievements.

Remember that you have fewer guns - weapons-enhancing tech isn't going to help nearly as much as more capships and more emplacements. However armor and regen techs (esp AM regen) help a lot.

Without caps OR frigs, you aren't going to be able to colonize.

So, its VERY unlikely.