This is a good topic, Ken.
I have seen angry, hard-hearted people come into a meeting or a group and try to steer it to their liking, complaining all the while that everyone else (including the resident old-timers) are doing things wrong.
Usually, these types move on.
Until they do, or if they don't, though, they are quite a headache.
I would be inclined to see how things work out in the short run and, then, move on to another group if possible.