I found this out on Mission 11. I gave myself tons of time to build a balance fleet because I knew mission 12 was going to be tough. So build 4 carriers and make each in a group number from 6 to 9 and shipyard as group 10.
1) group6 carrier build platforms only(5gun,5ion, 5gun, 5ion...etc)
2) group7 carrier build corvettes only(gun, paulsa, gun, paulsa...etc.)
3) group8 carrier build interceptors and bombers only(int, bom, int, bom...etc.)
4) group 9 carrier build frigates only(4trop, 4flak, 4 ion, 4trop, 4flak, 4ion...etc)
5) group 10 shipyard build BC, destroyers, and carriers only
6) group1 MS build none combat ships and backup builder
This way you don't have to wait for the right ships to be built. Make sure you use Pause when first jump into the new mission and max all your fleets out.