Pure capital ship fleets never worked against humans, as frigates and cruisers have much better cost damage ratio than capitalships at lower levels, and if you have many capital ships you will never be able to level them up as they share experience among each other, and a human player will likely focus on them if they have any sense for this game.

Capital ship fleets are only good against AI, I liked to play that way too, AI will lose huge fleets to my capital fleets, but humans will never, just think a bit, 5 heavy cruisers will easily kill all capital ships at lower levels, not to speak about javelis frigates built in number.

Subjugators are only good for repairing, and still sucks in that purpose too. Guardians require so expert micromanagement to maximalize effect I never build them (if you let them autocast abilities you gonna have a real bad time...).

Titans need somewhat more xp for leveling, and they share XP with capitalships, and you had many capitalships draining xp from titan, no wonder it didnt level up. And Coronata is worst against huge bunch of ships, even light frigate spam can kill it if there are enough enemy ships, Coronata has no area attack while all other titans have (but no titan area of attack ability can target corvettes and thus corvettes are good counter of titans).

Don't build Discordia for the area attack, it needs too much antimatter for it. It is only built for weakening enemy titans or capitalships.

Advent Loyalist is the 2nd weakest faction after TEC Loyalist, only the Coronata saves them from being helpless. It needs experience to handle them wel, TEC Rebel or Advent Rebel is much easier (don't try Vasari, that is nowhere fun, both factions are so OP if you survive till mid game...).

Corvettes are good against things like fighters do, so countering them needs same like you would build against fighters. Light frigates take almost no damage from corvettes and they are good for taking them out, and if you have a moderately big fleet try mixing antifighter frigates in it, if you can have more than 20 is fine (but don't forget, they are good against fighters, moderately good against corvettes and long range frigates, but suck against anything else, except you have huge numbers but they are easily countered by titan area of attack abilities). Oh and it is funnier, corvettes can attack bombers but not fighters, so fighters are good choice if you have resources for carrier cruisers, and if you are done with corvettes, just scuttle fighters and change to bombers to deal with titan capitalship or structure enemies.

Leveling Titan: attack the pirate base WITHOUT capital ship, so all xp will go to your titan, just dont let it die, you can retreat, repair it and attack again, if you can take all pirate ships you will have level3 titan from 0XP. BUT don't make the mistake, if you need the Titan for defense dont attack pirate base that would be idiotic, only attack the base if you can defend without it, and dont ever forget to repair it after this move.

Another method, if you are likely to win a major battle without your titan killed, try to win it without supporting capital ships, so every kill XP will feed your titan only.

LEVEL 9 ENEMY TITAN? LOL that should be avoided at all costs because all titans are massive threats to fleets at that level. AI can achieve that easily if left alone with another AI, take that warmachine out as soon as possible and disable its antimatter with capitalship abilities not to loose all fleet in minutes.

Guardian is good but you need to manage them well i dont have the blood pressure to always micro them well as their autocast sucks, it worths nothing if you have multiple of them using shield casting.

1 capitalship is enough, second big ship built should be your titan, not to drain much xp from your young titan. Further capitalships should be built for particular reasons like dealing with massive amount of strike craft, or disabling titan antimatter. Vasari has a strange strategy for massed capital ships but I hate vasari and i dont know much about them.

Advent starbase is strong especially the two area of effect abilities. and anyway, everything that is strong is good for the advent as it lacks such things.. but starbases shouldnt be massed, only 1 or 2 on key planets that you want to defend, or at neutral gravity well to make your trade network longer.

Updated guide? maybe there is one for rebellion i dont know, but the newer things are: corvettes have light armor like fighters and do composite damage that is good against capitalships bombers long range frigates and titans. Titans do good damage to anything and i think has capitalship armor, can be countered by many corvettes, bombers, titan, and capitalships.

there is a line in their file, frigaterole, so they will automatically target the thing they are good against but you should guide them to attack what you want, sometimes they waste fire on things they cant attack well, like light frigates attacking javelis...