I don't think they're over-rated at all, Jaraiya killed like four of the pain bodies, and if it wasn't for him they wouldn't have beaten pain, in fact it was his book that moved pain to bring everyone back and give up. Tsunade is sick, she is the only one besides the nine tails cloak that almost killed jaraiya, destroyed half a castle in like one punch, she's just got to get over her hemophobia. Now Orochimaru is so feared, even while existing in Kabuto's body, people fear him. Sasori used kabuto just to get an upperhand on the guy. In fact we've seen him defeated three times in the manga (the third, sasuke, itachi) and he's still kicking and a huge threat. I think Mifune just had the upperhand on Hanzou with his speed and technique, like zetsu said during the battle of sasuke and itachi, A master with a stone can beat a novice with a shuriken. By eliminating his ninjutsu, he put him on his level, where he is the best.