I think team 2's got this. Muu's being hidden by his invisibility and mist. Seeing as the manga's confirmed that sensors can't find muu nor trollkage, tobirama's sensing feats are useless while muu's sensing feats allow him to perfectly find tobirama and hiruzen, even if he can't find his own team mate. in fact, the only way to find these two(when their jutsu's are active) is with some form of contact sensing. Neither tobirama, nor hiruzen have contact sensing as far as we know.
What's worse is that, if trollkage is hit, he bursts into water and is completely unaffected by the blow. Tobirama's kenjutsu, suiton and hiruzen's entire arsenal, bar raiton techs, are all useless against trollkage. While, against muu, if he's hit, he can instantly use fission to save at least half of himself. The fission is so fast that even someone who knows him didn't notice that he performed the fission, nor did naruto even sense that it happened.
Jokey boy, Jinton, mirage, hydrification, fission, flight and sensing/counter sensing abilities make these two a deadly two man team. Good thing they only ever fought against each other in the manga...