After some thought and play, I've come up with some Ideas about how unit counters work in sins.
There's aleady some excellent information about this here: https://forums.sinsofasolarempire.com/?aid=177602
But this is how I parse those tables.
FRIGATES:
I divide frigates into two groups.
1) Non-Combat frigates: Scout, Colony, Seige.
2) Combat Frigates: Light, Long-Range, Flak
The non-combat frigates aren’t used for shooting ships, so we’re not going to worry about them too much. Among the combat frigates though, there’s a very clear rock paper scissors matchup.
Long-range beats light.
Flak beats long-range
Light beats flak.
All three combat frigates do pretty well against the non-combat frigates.
Huge amounts of scouts MAY do okay against frigates.
Huge amounts of Seige frigs, MAY do okay against cruisers.
Light Frigates also do very well against cruisers, except heavy cruisers.
LRMs do pretty well against larger craft.
Flack frigates destroy strike craft. (But you must have critical mass, or else bombers will rip them apart)
STRIKE CRAFT:
Fighters and bombers
Fighter do well against:
Bombers, Non-Combat Frigates, and LRM Frigates
Bombers do well against:
Structures and Heavy Cruisers ONLY. They do NOT do great against capital ships. Okay, but not great.
It’s interesting to note that bombers do not cream capships. They should primarily be used to take out static D. Which they are quite effective at. Similarly, fighters do pretty well against LRM frigates, which can upset the frigate matchup a fair amount.
CRUISERS:
There are 4 cruisers. 2 of them are essentially non-combat.
The 2 utility cruisers do okay agasint other cruisers though.
Heavy Cruiser:
kicks ass against everything. Like structures, only very vulnerable only to bombers and capital ships.
CAPITAL SHIPS:
Kick ass against everything. Only really vulnerable to other capital ships.
STRUCTURES:
Bombers are your best bet, LRMs do okay.
Turrets are good against light frigates and okay against cruisers. They are similar to LRMs.
RAIDING AND HARASSMENT:
Note that there are two units that can do damage to a players infrastructure quickly, in fact they excel and perhaps even specialize in this purpose.
Seige frigates can get in, reduce a planets population, and get out quite quickly. A planets HP takes a while to take down, but population dies fast. Use this to your adantage and keep his credit income reduced. (if he researches defense upgrades, it will be harder,b ut at least you've forced him to do that much)
Bombers are strong against structures. They are the only thing that is strong against structures. A small group of carriers with bomber wings can sneak in, kill a research lab or extractor or trade port, whatever and get out fairly quickly.
Seige frigates are available quite early. And are excellent for early game harassment. Bombers are avaialable a little later, and are good for mid/late game harassment.
Like any RTS, harassment is critical... and is probably what will win you a close, competetive game. These are the two units that will get the job done!
SOME NOTES:
The counters are pronounced but not severe. It’s not like in starcraft where a reaver will instagib a boatload of zerglings. Doing well doesn’t mean a single one can kill a whole bunch. Basically if you have an equal number of light frigates and LRMs, the LRMs will win probalby win, but they will not stomp the other guy. Don’t expect to come away without any losses just because you have the hard counter. If the enemy has a spam of a certain ship type, you're going to need a spam of the counter ship type to overcome decisively (although you may still take heavy losses).
Scouting is critical. Scouting is critical. Scouting is critical. There I said it. The game makes scouting easier than any other game I've ever played. Probably because it's more critical than any other game.
These ideas are upset a bit by racial differences. For example, the fact that the Advent don’t have a Long-range frigate. And the cost/damage of the Vasari light frigate and LRM frigate are switched. As a result, the races turn out to be quite assymetrical. But the conception I've described should be a great starting point to get into the game as TEC, which can then be adapted easily to play the other races.