mu. kisame cant see or track him since he can fly. and flight means he can change the weight of himself or others. ergo a weight enhanced punch/sword slash would do nicely to cut through samehada. sensing means he cant be caught off guard, and probably would know his jinton loses to great shark bullet.
Muu is very strong but i think kisame has a better chance at winning.If muu besomes invisible kisame can use giant water prison so that way muu whant be able to come near him.If muu uses jinton than kisame will use daikoudan,and muu always uses jinton at the beggining or the middle of the fight.At hand to hand combat kisame is a lot stronger than him and muu doesnt know about samehada so kisame will suck all of his chakra.kisame thakes this 8/10 times because muu is very smart and he could trick him at the begining by cutting his head with a sword.