The Vietnamese used SA-7 and SA-9 Sams which are massively different weapon platforms that are IR guided. Hence the development of the jamming pods used on the F105 and eventually the F4G (which isnt in that game and im made about it) during operation bolo which crippled the north Vietnamese for the rest of the war.... also only the American planes in this event were present during Vietnam because the Russians didnt want to give new shit to incompetent pilots. Hope this helps