From that I'd say 20-30 cobalts max, if you see your opponent going carriers, then start pulling out some other ship types.
If your fleet has carriers with fighters and LFs (e.g., cobalts), and your opponent keeps bringing in carriers, then keep pumping out LFs. The carriers you have will keep his SC busy and your LFs will roast the carriers; why build anything else (except
PS. Cykur, you're my hero. Because ICO was sucking so bad yesterday, I actually played a SP game...as TEC (the irony)! Anyway, TEC still has a really slow start, but man...vasari repair bays look like infants compared to upgraded TEC repair bays (15/sec vs 40/sec). Their anti-SC cap abilities also rock. The thing that I still love the vasari for, and always will is their economy requires NO imperial labs and those phase missles can pwn siddy's progen battle ball.