We have around 300 fighters. If we try to make 300 TFX it will cost insane amounts to build and operate. 100-150 TFX and 300 something drones would likely be cheaper to operate and UAV pilots are considerably easier to train than fighter pilots aren't they? I mean if we use quoted 100 million $ per unit and considering fighters have a lifetime cost about 2-3 times that of purchase price, we could be looking at 90 billion$ for just fighter fleet without anything else.