By using allied teams, you could have up to 18 ships in combat at one time.
If that's not enough for you, try taking the Rommie KHK, and adding 2 R-RHKs & 2 R-FHKs as PFs. Do something similar for all six teams, and you have 90 ships in the air at once.
If that's still not enough to bog your computer down, use carriers for the PFs.