Mangetsu can use all the swords but we never got to see how good he was with them, so this is partly guessing, i think Kisames larger chakra supply would help him to win but if Mangetsu is good enough to use two swords at once i think he could win so as i said this is mostly guessing for now

i think mangetsu's also strong. though i don't know much of his chakra supply. but it would maybe him. in fact, suigetsu called him the "Second Coming of the Demon". xD

I don't know much about Mangetsu... But Kisame has a lot of chakra, and he almost doesn't tire. I'd say Kisame. But still, I don't know much about Mangetsu.