considering the fact they dont know any of human paths abilities, then one touch and they are screwd. neither can solo both pein and obito so if one goes down they both go down. and one of them has to go down, unless they just happen to kill human path first. also if human path touches them then not only does pain take their soul out, but he gains all the knowledge which in either case would give him complete knowledge of both the abilities and weaknesses of both sasuke and itachi. if they deal with human path first there is a chance they can get lucky. i think its obvious that a live itachi can solo ms obito considering he almost did it after he was already dead. people say it was a surpise attack but with a live itachi there would be plenty of chances for surprising obito again. itachi cant kill obito with pein protecting obito though that makes it alot harder. so i think pein and obito win this easily but if either sasuke or itachi just happen to kill human path first without knowing the threat it poses then they have a chance at getting lucky with extreme dif. notice i still said lucky, so dont look at the extreme dif. as they can do it because i dont think its in their abilities. not to mention its only a matter of time before human path revives and catches one of them offguard which will be the end for both of them.