Every weapon (excepting the obvious fantasies) in AC games is real and appropriate. The "basic" missile on an F-14/15/16/18 is an AIM-9. A MiG-29 has an AA-8. F-2 has AAM-3.
The "XMAA" will be an AMRAAM, Meteor, or AA-12, depending on what plane it's on.
XLAA can be AIM-54, AA-9, etc.
I don't know if the game actually tweaks the specs for each weapon, or simply makes them all the same. (as in, will the game actually make a Meteor slightly different than an AMRAAM, or simply gives all XMAA-type the same specs)