Steam makes Wine prefixes for every game so they don’t interfere with eachother.
To answer OP: each new version of Wine and especially Proton introduces changes to fix one or more game that can potentially break other games. That’s why if a specific Proton version has been known to work for a game, your best bet is to use that version for that game. But as always with Wine on Linux though, YMMV, so trying out several versions to see which one works best is a good idea. I’ve found that most games work well with latest GE.