alternately, you can open the squadpsifighter.entity and squadpsibomber, etc for each of the races and adjust the numbers of ships in each squadron.
Strikecraft can be devastating, and a good counter, though you may not want this, is too make the fighters and the bombers more fragile, take some of their hull and shield and armor away, but leave the same damage. In this way, they are still powerful, but they dont last as long. 
Take care,
Keep Gaming and Modding!!!
-Teal