I think your what-if just doesn't work. I'm sure we've all seen the quote that the Crusader III was a brilliant aircraft, it just happened to be up against one of aviation's all-time greats at a time when the Government wasn't willing to pay for both.So I've decided to crowd source it here as a what if game.
The F-4 was always going to win if it existed, because it was one of the most versatile airplanes of its era (not least because it could carry EIGHT missiles into combat, a vital asset at a time when the aircraft didn't have a gun and the missiles were badly behaved to say the least). What you need to posit is that either McDonnell-Douglas never built it or somehow failed to make it the success that it was. THEN your scenario works, but not otherwise.
Is the R-530 even compatible with that? Or is the pylon mounting we see in history merely a function of the aircraft that carried it?Hang four R-530 semi-recessed on the flanks (Phantom-style)