The Mac book 3 pro doesn't have any sort of dedicated GPU though right? Unless you have a customized system at least that's what store pages for the laptop tell me.
But if that is the case then you should have zero issues running the game (not a Mac guy so I dunno how it would play tbh). All I can say is that if your running a side loaded windows and the game it shouldn't be an issue unless it's not correctly connecting to your GPU drivers. Not sure.
As for the gog page I do not control what they put there so they likely pulled it from some other site. But I'll talk to them about it.