For me, Sakura somewhat ruined Tsunade's rep. If she's getting surpassed by the pink haired ****, then really - her skills must have peaked and fallen long ago.
I think it's hard to tell sometimes, a lot of the canon is inconsistant when it comes to these three in particular.
Jiraiya less so... but yeah, Orochimaru defeated a Kage and various other nin - showed great skill in other battles yet he was easily defeated by Itachi, later Sasuke somewhat and he never really matched Sarutobi.
I'd rate the perv slightly above the other two due to being a Sage. But then again, Orochimaru did well against a Tailed-Naruto, whereas it almost killed Jiraiya... still, different circumstances I suppose.
They're below Hashirama, Tobirama and Sarutobi. Perhaps more on par with Minato? Kage level, sure... but none are exactly 'God of Shinobi' material.