Ironically, it should be easier to model the modern fighters than the ones from the 80s and 90s. After realizing there was serious pilot workload overload, planes like the F-22 and F-35 are being designed to be more like the sims we played in the 90s with "god's eye radar" turned on.
You designate the target, choose the weapon (maybe that is even done for you based on range to target), give the authorization to fire and the weapon goes when the time is right. No worries about slewing this or activating that or remembering the right sequence. Point, click, and shoot.
I think TK could do that easy right now with his engine. The targeting boxes could simply be on your HMD. The only real change is the new jets can do AA and AG at the same time without changing radar modes.
The rivet counters are immaterial, anyway. Give me a sim where it FEELS real, where real tactics work and the enemies act real, and that's enough. Sure if I can't break Mach 1 in an F-15 I'll be annoyed, but whether you're going Mach 2 or 2.5 in 5 mins or 8 doesn't really matter to how you fly and fight, the whinerealism people to the contrary.