DoD developments are a lot like the Apollo program having tried a Saturn V and a moon landing on the first mission.
Quantity has a quality all its own. We need some balance and one of the things we don’t have is enough numbers.
Take a platform like the F-15SE, build a bunch of them and make improvements modular.
And by "modular" we should mean that a superb sensor system (for example) from the F-15 should also be able to fit into a slot on an F-35.