Well, I don't know if it was mentioned in the on-going argument, but without Jiraiya's sacrifice/information, to Konoha/Naruto, Pain wouldn't have been perceived as what he is right now. Instead of it being 6 "bodies" with 1 specific ability each, it'd be 6 Akatsuki's attacking Konoha. That completely changes the game, strategically.
Knowing that each Pain can only do one thing is a huge strategic advantage. Would they have figured that out eventually? Probably. But Konoha has managed to dodge complete annihilation by having this information BEFORE the attack started.