speaking of which... how is dan (Tsunade's brother? boyfriend) considered a super-strong ninja?
sure, he might be skilled, and have good genes (same blood as the first Hokage, does that make him an Uchiha?), but he didn't appear to be anything special, just an important person for Tsunade.

besides, if he can bring back people who lived ages ago (longbefore Orochimaru started his hideous experiments), why not go and bring some really old ninjas to life? old kages for example, maybe someone who isn't already a character model?