I had a pond with lots of Bullheads that a few LMB got into. Then the few LMB spawned and the following year very few young Bullheads were seen. I can still catch big ones but the little ones have been feeding 6" bass this year. I think BH will be a lot less abundant in future years. Good or bad that's what I have seen happen. I don't mind having BH in the pond, but LMB are fine also. So if you put some in they need to be adult. So I agree with what snrub is saying.