Am I pretty much limited to BnZ and running away otherwise?

I’m specifically struggling with how to approach positioning in these matches. There are tons of guides for things like dogfighting, defensive flying, aiming, etc., and for those it’s usually pretty easy to spot your mistakes and figure out how to improve. But I’m a bit lost on how to actually position myself or set up fights properly. Right now I’m playing the Mirage IIIS and just getting absolutely rinsed. I watch videos of people flying it and they always seem to be in spots where they have someone low-energy in front of them, and even with my terrible aim, I could land shots in those situations. But my problem is obviously getting into those situations in the first place — and I’m lost on how to do that. I can imagine myself climbing to 3 km, going left, doing a 180, and diving to pick off a base bomber — but then there’s a MiG-21bis on my six, 5 km out. If he really wants to chase me down, he eventually can. If there’s even one more non-subsonic enemy with him, and I try to reverse him or dogfight, I just get third-partied by the second guy. So is my only hope airfield AA? Or am I just screwed anytime someone faster decides to chase me down and there’s a third party around? #warthunder #VideoGames #GameSkills #Steam