In that scenario its incompatible desires. No one's an AH.
In my players pool I have some who will play anything some who will only play 5E or OSR. Others can only make one times slot.
The ones who will play anything, can make both time slots and are keen on board games or whatever will have advantages over those who can't/won't.
My next game might be AD&D (run alongside 5E) and not everyone might be keen on AD&D. Might be Star Wars I do get sick of D&D.
One timeslot is 5E, ones OSR. I'll try and get everyone in at least 1 game I can't gurantee both.
I can't compromise on time slots. That one shoukd he obvious. Family/work>games.
I'm looking at a third game either an occasional one or alternating bi weekly or something. That's a tonight and Sunday problem.
At some point it's here's when I'm available and what I'm running. You're invited up to you if you want to play. Once they get past that (eg I don't want to play whatever) we can have a discussion over what's in said game.
I'm not running Fallout RPG even if every player asks.
So, if I'm understanding these examples correctly (numbered in listed order)
1 (only 5e/OSR), 3 (some folks may not accept AD&D), and 5 (you will never run Fallout) are about system selection, and thus occur before any sort of gaming even begins. Thus, not applicable to what the thread is about, which is tools for assuaging/preventing conflicts in the preparatory and execution stages of gaming.
2 and 4 are time slot selection, which is not an issue of
actually playing, but of whether play can happen in the first place. This isn't a matter of conflicting personalities or disagreements, it's a matter of whether it is even
possible to game at all. So, again, has absolute bupkis to do with safety tools or compromise.
Once play
has actually begun, so long as the people involved actually did communicate and express their interests properly etc., you have said "we can have a discussion"--meaning, you are amenable to finding a way to make things work, even if one or both sides ends up not getting the full and exact, specific details they originally set out for. Yes?
Because if so then that seems pretty clear to me that you
do think a reasonable solution can be reached by reasonable players in actual-play situations, so long as the participants (DM and player alike) are in fact participating in good faith.