I found out that after you reach some critical mass of bombers in your fleet(20-30+)and some support you basically become unstoppable .Reason being that bombers cost nothing , fly very fast and 30 of them can kill any capital ship very fast. You attack basically as soon as you enter the well, while other ships have to travel to you first. Flak frigs or no flags it doesnt really matter -you take out caps in first minutes of a fight and you may lose some bombers which will regenerate anyway
I dont really see any other ship combination being nearly as powerfull as carrier fleet (missile frigs are nice in the beggining but thats about it).