I wouldn't know about that .. a fully powered kimimaru could be very powerful orochimaru would have prefered him over sasuke if he wasn't sick ...
Those bones of his make for an incredible defense and offense set
besides pain toyed with jiraya same with naruto if he had wanted to kill him he could have ... with ease
meh he didn't really "play" with jiraya seeing that jiraiya managed to kill a total of 4 bodies and nagato admitted that if jiraiya knew the secret from the start that jiraya would've won for sure.
and if for some crazy strange reason they needed more man-power, BAM orochimaru summons 1st, 2nd, 3rd, 4th hokage and that buys time for jiraiya to go sage mode.
so 1st, 2nd, 3rd, 4th hokages, Sage Jiraya, Orochimaru and tsunade healing any wounds.
Yeah, nagato would be destroyed.
Actually, if orochimaru summoned the 4 kage's with sage jiraiya and tsunade backing him up, I don't think even So6P or Juubi could beat that. In fact it's pretty obvious that they couldn't....
bottom line, all 3 sannin is a force only DBZ characters could beat.