I love Jiraiya but if he doesn't swear a binding oath to give us literally all his lore and knowledge as a ferryman's fee with a decent down payment prior to resurrection then I have reservations about bringing him back.
I think it's overwhelmingly likely that he immediately recognizes the magnitude of our achievement and pledges himself up our cause, and apologizes profusely for dying before he was able to make good on his promises, but if he isn't willing to follow through on the material terms of commitments he benefited from immensely and made freely, who's to say he doesn't welsh again?
We've spent a lot of time getting screwed and played by people who knew that we'd prioritize the public good. If we open a portal to the afterlife and Jiraiya doesn't promptly signal understanding that he owes us literally the rest of his life, I think it's time to re-evaluate how we handle negotiations. He is not coming back as clan head. He is coming back as a member of the clan under our authority, and if that isn't acceptable to him then he can find his own damn way out of the afterlife.
I'm possibly conflating his willingness to marry Mari and his general willingness to keep his word, but the two are IMO at least correlated, given that his memory is intact.