With advent u must have more units than he has early on. Priorities in building or researching have to be met. Vasari ai's buff up there units so fast by the time they clonize the third planet and 1 or 2 asteroids u r facing light frigates with 4-5 armor. You must work your way to having 2 hostility temples, 1 harmony temple at home or combined with an asteroid. Go on to 4 hostility, then add another 1 harmony temple. Research armor/hull, illuminators and defence vessels and trade.

Keep going with armor/hull from there on until u reach the domina at 6 hostility temples and research it and perseverance ability so it can regenerate the hulls of ships and strucutures..  Role out domina cruiser but do not issue it attack orders, thus turn auto attack off.  it must also not be in a fleet but accompany a fleet. repair ability requires it to be stationary or not moving. So make it hold position during engage ments of your selected fleet. Its a complicated matter but thats the advent for u. Big guns that need more brains. Research the crusader at this point cos by now expect heavy cruisers knocking on your door step from the vasari..

Next go for the shield upgrades up until u get the iconus guardian. there on supple-ment your fleet.. scouts, desciples, defence vessels domina, crusaders----- against starbases go with iconus guardians but there should be more domina in any of your fleet against the vasari..

During all this time u need to role out as many units as u can and make sure u have atleast 1 trade port on the major asteroids and planets. pump out as many scouts and desciple complemented fleets with defence vessels. then add illums. Its brain busting work.

Your first Capital ship is always the mother ship for cost reductions from 15% on the first planet. Try get to level three before the next major planet for the 30% cost reduction. With the mother ship i tend to disable shield regen and just use malice.. don't ask me why: im just too offensive so wanna spare some anti matter. 

End result is advent ships with some serious hull regen and shields and available in great numbers cos of low cost tier 0 units.

Forgot , that starfish( Solanus Adjudicator) Cruiser packs a punch... take 2 or more with u to kill starbases with your fleet

Thanks a lot, all of you. I wish I'd saved the game replay from just before I posted this but I forgot. I'll go check out the posts suggested, and this info will probably help a lot, seeing as my biggest problem always seems to be battle. I love the Advent but their special abilities and support ships take a lot of management...

Orgov is not correct. It's OGROV TORPEDO CRUISER... That kinda bothers me.

1. Scout quickly

2. Find choke points

3. Build starbases at choke points as soon as humanly possible

4. Have repair platforms, and maybe repair cruisers later

5. Upgrade starbases as needed

6. Fill every spare logistics slot with trade ports

I've found that if I follow this strategy, I rarely have to upgrade my initial fleet supply capacity until I have more money and research than I know how to deal with. I've never needed to go past the first 100 -> 250 supply upgrade. This has worked for me against every combination of AIs, up to cruel 3-on-1. It enables you to have the strongest economy possible (while having virtually no fleet) but the starbases insulate you from nearly any attack, so you can research and fortify and save up to your heart's content, until you feel like building a fleet, at which point you will have virtually unlimited funds. 10+ capital carriers can allow you to take down nearly any AI fleet with ease, and if you have a decent sense of tactics, you'll take no casualties. (Of course, they'll take a LONG time to level up, but that's all right.)

All you really have to worry about is if the AI is TEC and creates masses of more than 5 Ogrovs to attack your starbase with, which'll do lots of damage unless you take them down quickly. (Use fighters!)