Naruto & One Piece are different worlds... You dont say Rayleigh wins cuz he use haki ?!? Then Jiraiya use Bunshin, Seal or Genjutsu every tricky jutsu he can use !?! This not a good approach at all.
They're awesome chars and mentors. They're my favorite characters in their series.
They're bot has intelligence
Jiraiya is better H2H combatant and martial artist then Rayleigh
They're both has same level of experience
Silver Rayleigh maybe a little quicker than Jiraiya
But Sage Jiraiya faster than him or same level
Jiraiya stronger than Rayleigh
And Conqueror Haki wont work on Jiraiya J-Man has a sheer will power..
They had same level stamina maybe Jiraiya little better than Rayleigh (Sage card)
Jiraiya has a better support stuff... Toads, Kunais, Paper Bombs, Traps etc etc
I think Regular Jiraiya take this with mid-high diff. cuz his more skilled and more smarter on 1on1 fights...
Sage Jiraiya win this low diff.
Why should these two even fight, they're too awesome for that. I say Rayleigh and Jiraiya get drunk and pick up women 35 years younger than them.
and this is a great approach :)