Re: Possible scenario
"unnecessary/late/ineffectual weapons systems" "like the F35?"
well, people used to say bad things about the M-16, too, when it first came out. nowadays, after a few decades of serious use and tweeking, it's probably one of the best small arms any military might have in its arsenal. IMBO [In My Bombastic Opinion] it's better than an AK-47, though AKs are probably cheaper to make [it was a design feature of the AK to be cheap/easy to make].
Give the F35 some time, so the bugs can be worked out, and the benefits of having a common airframe for what is basically 3 different kinds of aircraft will make a lot more sense. Sometimes you have to look at "total cost of ownership", and how military supply systems work on ships and when deployed in the field. Keep in mind that you need SPARE PARTS for all of those planes, to deal with war damage and normal wear and tear. And so, the basic design feature of 'commonality' is a serious tactical advantage, from a supply/material standpoint.
[having been in the military, having been a 'repair parts petty officer' and had to deal with the navy supply system, it's important to consider THAT aspect, too, with respect to weapons systems and availability and so on].
In Sun Tzu's book, "The Art of Warfare", he talked about how important it was to make sure your troops were properly supplied for whatever campaign they were to be sent on. Supplies are extremely important.
Anyway, that's my $.10 worth on the F35. It's really still a "beta release". Then again, in a time of war, sometimes those 'beta release' weapons make all the difference. I mean, how many awesome planes in WW2 received the 'P' designation for PROTOTYPE? And I think it was the P51 Mustang with the Merlin engine that really did the trick to help end the war a bit faster...