Jiraya in SM from the beginning solo's high diff. With Itachi healthy.. low diff. Itachi is superior in almost every way with Jiraya to back him up. Sasuke uses Raiton, Shima uses Futon, Sasuke uses Katon Fukasaku uses suiton or itachi uses suiton. Jiraya and Itachi katon>Sasuke's Katon, Jiraya + Gamabunta oil katon>Sasuke Katon. Sasuke has the elemental disadvantage, clearly.
Defense: Itachi Susano'o and Jiraya SM body vs Sasuke Susano'o Itachi has Yata mirror, so clearly he has the better defense then Sasuke's. Itachi doesn't last long because of his stamina, but Jiraya has an extraordinarily large chakra supply, as well as a extremely resilient and strong body in SM.
Attack: Clearly Itachi with his Totsuka blade, what can Sasuke do against it, one shot and he's dead. Jiraya can use earth from the underworld (to slow him down) while Itachi uses his totsuka blade. The ninjutsu is out of Sasuke's league so no debate in that, if Itachi gets hit by Amateratsu, Jiraya can use the fire seal and take away the Amateratsu even if it did burns, or was on the outside of Itachi's Susano'o doing no damage.
Taijutsu: Jiraya SM and Itachi clearly. Itachi is much faster than Sasuke, and Jiraya has the clear upper hand in strength, sensing, and speed. Jiraya in SM can't be compared using frog kata to Sasuke as he is on an entirely different level. He can punch with Senjutsu enhanced strength (don't see the punch) as well as sense most the attacks the user is about to do.
Intelligence: Clearly Jiraya and Itachi are more intelligent, as Itachi is the most intelligent shinobi with Minato in Narutoverse and Jiraya is almost as smart, but in different ways.
