Kakuzu has this in the bag. If danzo's wind/wind attack blew off a layer of susanoo, imagine what kakazu's fire/wind/lightning would do. Susanoo is also bested by tentacle attacks from below.Taijutsu wise, kakuzu has already proved that his tentacle rape attacks can best the sharingan. If kakuzu gets hit by ameterasu, he could easily shed whatever is burning and still have plenty of thread left. If sasuke tries susanoo it would be picked apart by the hearts, and if he doesn't he would b facing 5 different extremely powerful attackers. Unlike kakashi, sasuke doesn't have clones to mislead them. It's also alot harder to get kills on kakuzu than against danzo who fought recklessly and didnt even bother dodging. Iron skin gives him an immunity to everything but his lightning techs and ameterasu.