Bobad, if that day of concern comes, will the LMB be able to cooperate? What if the BC snack down on the LMB instead?
If a crappie comes along that can eat my 20"+ LMB, then I'll be concerned. No, wait! I'll be delighted!

Kidding aside, I've always thought crappie are very cover dependent. I think they get out of control when there's lots and lots of cover. I don't have that problem, but I know exactly what you mean. I've fished ponds that had way too many small, stunted crappie.