You're joining a new band. They do what they like to do. If you like that, then it may be a good match. If not, I think best to move on. Joining a band with questions like yours doesn't look like a recipe for success. By all means, talk to them about what YOU would like to be doing, maybe they're receptive and it's great... but you can't expect to join a band and change them into what you'd like them to be.