In the presence of aim-120 and r-77 you have to stay low and use terrain masking. The "knights of the sky" High altitude approach will just turn you into an AMRAAM catcher's mitt. Take the MiGs approach and ambush from terrain.
The jamming pod doesn't work. If you cant put an AMRAAM into a mountain you arent going to shake it. The '21 really doesnt stack up against 4th gen fighters.
I think it's an AN-2... its' advanced propulsion features are its' ability to fly in reverse in a stiff wind, and a drunk Eastern European with a pencil and a legal pad can do some mighty fine terrain mapping
The thing that stuck out the most in the USAF '78 manual to me was the lack of rwr.
I think the F5e would work well in "Blue Flag" style mp scenarios as a local defense/quick reaction fighter like the 21bis is in the current Blue Flag.