I'm guessing that each session will probably last around 20 or 30 minutes at the most, so if the same 5 people stick together then maybe 3 or 4 of the 5 players would have a chance to be the monster in an hour, even if it's just randomly picked. I'm hoping that they'll implement a better system than just RNG though.
I tend to pick support type roles in co-op games, so when with friends I;d be happy to play as hunters, however I wouldn't want to be using a support role with random players online, so then I'd prefer to be the monster.
I tend to pick support type roles in co-op games, so when with friends I;d be happy to play as hunters, however I wouldn't want to be using a support role with random players online, so then I'd prefer to be the monster.