I am sure lots of people with more experience and know how than I have thought this out, but with the massive incompetence in all things government, maybe not.
In my (not-so-humble) opinion the variety and purposeful effectiveness of our multiple aircraft designs is a huge part of what made US a superpower. ("Made" as in past tense.)
Simple example:
The A10 does things in close air support far better than F15, F16 or F18s.
The guys on the ground want the A10.
But you wouldn't necessarily want to fly it against a MIG29 in a dogfight.
Having only one fighter jet in the arsenal strikes me like saying that we'll only have one gun for every soldier. Then you tell your design team you want an "Assault/Long Range/Sniper/Bolt Action/Select Fire/Pistol/Grenade Launcher."