Yeah, IMO the F-15 has proven to be the better of the two (over the 16), and its combat record is impressive to say the least. Another advantage for the 22 is that it is stealthier than other air superiority fighters (theoretically, of course - I can't prove it
).
As for the F-5 and Starfighter, I might be wrong but I was under the impression that they were never really intended for front line duty with the USAF anyway; seems like I read (a looong time ago) that they were developed for use as MiG stand-ins in training and for us to sell to "friendly" nations (back when that sort of thing was less frowned upon). But again, I could be wrong.
I agree that having the J-10 in "numbers" might pose something of a threat, but think the USAF's definite advantages in stealth and night-strike capability (turn-around/number of sorties we can fly, too) would *probably* counteract that. Probably. Hope it won't take combat to bear that out, though.