I always thought weekly polls were overkill; reduce to bi-weekly maybe? At least then you won't have them stealing the activity that could go into newer topics.
Also, you could restrict discussion to be strictly canon in B/W, if there is cross over happening. So, anything that is comparing between games (if that is happening) isn't allowed.
B/W is a big game, from what I remember, and there is a lot of stuff that can be discussed in here, so it is just about focusing that topical stuff like.
/no idea if relevant, was told to post.