McDonnell's big at bantam anyway he should be moving up, Munroe would be crazy to come down. Plus Maloney must still be angry at him so the fight is far from guaranteed to happen.
Cant see Munroe making the weight but if by some chance he could make it and do it comfortabley then surely he would have a bit more pop in his punches? If so then he should take Mcdonnell but thats a big IF.