My thoughts on Base Jiraiya:
Scenario I:
Since summonings are restricted I'd say Sasuke wins high-diff just because he's faster.
But if there are shadows being made by the Sun (it's a sunny day at this location) then I think Jiraiya can survive long enough using Needle Jizo to use his Shadow Manipulation Technique at short range (assuming Sasuke is trying to get through his Needle Jizo with a Chidori) and momentarily confused Jiraiya can use a whole slew of Jutsu to defeat Sasuke so mid-diff Jiraiya.
So on average this scenario goes Jiraiya's way high-diff
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Scenario II:
If Hebi Sasuke had complete control and respect of Manda then I'd say this goes in Sasuke's favor but I don't think he does, which means Hebi Sasuke would have to use genjutsu on Manda to control him which uses chakra by itself. Having plenty of toad summons in his arsenal that are loyal to him, Jiraiya doesn't have to expend chakra whilst their already summoned (does expend chakra by summoning). If Jiraiya can summon Gamabunta and at least two more giant toads and I can see them dealing with a controlled Manda (plus I feel Jiraiya at this point has had plenty of experience with Oro's snake, and Oro has mastered using them so I think he'll be able to handle a less experienced "snake-wielder" if you will).
In terms of Kirin on such a sunny cloudless day there's no way Sasuke would even be able to use it, as without clouds he wouldn't be able to heat them up to create lightning (feel free to tell me if this point is way off base).
If he IS able to use Kirin I don't see Jiraiya surviving as he doesn't have a good enough defense to deal with that much power, so Hebi Sasuke high diff in that case.
In this scenario Jiraiya can also use Toad Mouth Bind to catch Sasuke, and where Sasuke would have no way of escaping because at this point he didn't have Amaterasu.
So in this scenario on average Jiraiya high-diff, and that's being generous to Sasukes resilience.
P.S. Saying Hebi Sasuke can take down SM Jiraiya is pretty bogus IMO.... he can just use demonic Illusion: Toad Confrontation Chant (sound genjutsu > visual genjutsu) .. so SM Jiraiya low-diff (plus he's got a rasengan that can level a mountain)