Even if exhausting, a rampage of Susanoo which is backed up with Amaterasu and Tsukuyomi appears to much for them. There is no way for Kakuzu and Tsunade in winning this, since a single eye contact (which can be provoked by Itachi even if latter two will try to avoid) destroys them. Trying to avoid eye contact (while still carrying the risk of being caught with a finger or crow) proves difficult since it's a matter of habit and being concentrated on avoiding eye contact would restrict them and leave even more openings for Itachi , who can easily fool his opponents with feints and Genjutsu to land great hits in the smallest gaps. And not only that they couldn't dodge Amatersu in any way, if avoiding eye contact because of Tsukuyomi, their death by Amaterasu - which usage can only be noted by the eye - is signed. Generally speaking, Itachi had no problems in one shotting Sannin- and Akatsuki-Level Shinobi with a mere Genjutsu for the reason Itachi knows how to catch the victims off guard easily and unnoticed, so especially the Mangekyo Sharingan - even with the Totsuka and Yata restricted - would prove a too overwhelming power for them.
