If you want to fly by a certain set of rules, the DA is open for that. Once in the MA, you know anything goes. It is a simulation of COMBAT. A sergeant major told me once that combat is a team sport. So if you are engaged with a 1v1 and someone else comes in, well thats not fair, that's combat.
Sometimes I ask someone, hey you ok with that plane down there? And if they don't answer, or they say hey give me a hand, I come in, often times at a disadvantage for myself. If they say no go away, I got this, I go on and hope that he doesn't screw up and allow the OPFOR plane to get away to do damage to my mission or my team.
When we are suppressing a base for a take, you bet I will vulch you. That is why I rarely up from one of those bases, and I understand I may get vulched when I do. I up elsewhere and come in on top to break up the vulch. That is part of defending the base.
In short, I know that in the MA anything goes. I expect it. I use mission planning and tactics to try to stay alive and get home. Staying true to my team, to my wingman, are honorable.