The word "prime" refers to any individual at their peak of ability, so in this context we're referring to ninja strength and ability. The Sannin who lost to Hanzo aren't considered prime at all, they still had a journey of strength to go before reaching their prime. Jiraiya didn't even have rasengan, nor did Orochimaru possess his kinjutsu arsenal and his arsenal of abundant jutsus, so that definitely isn't them at their prime at all. The Itachi that "wiped the floor with Orochimaru" is pretty overhyped and far fetched, Orochimaru wasn't even fighting Itachi to begin with, it was only an encounter where Orochimaru tried to steal Itachi's body, Itachi backfired his plan and Orochimaru, realizing how vain it is to steal an Uchiha of such high claiber's body, decides to retreat. Nothing more nothing less. And orochimaru didnt even have his full arsenal of kinjutsu even developed, so what's your point here? Remember, prior to joining the Akatsuki Orochimaru was kidnapping leaf citizens for experimental use, but after being caught by Sarutobi and leaving the leaf village he put his experiments to a minor halt, until he left the Akatsuki and proceeded with his endeavor to learn every jutsu there is. Now, after leaving the Akatsuki Kabuto joined him in his experiments so he learned and peerfected more jutsus than ever.
What point are you trying to make about Jiraiya needing sage mode and losing to the animal path? Number one I said who can solo SM Jiraiya, meaning he already starts in sage mode, and the remaining prime sannin, at once. Number 2, animal path soloed 4 of the Anbu officials at once easily, while Jiraiya who, was intentionally not fighting with the animal path in order to activate sage mode, subdued almost every boss sumoon of the animal path. Does that sound weak and unimpressive? Number 3, who wouldn't retreat, he knew absolutely NOTHING about Pain, no one can dream of beating Pain without info. In fact him coming up with a plan is very impressive and exploiting it to full use is another impressive feat, which managed to kill 3 bodies of Pain at once. "As soon as Nagato got serious, look what happened"? LOL, funny. Dude he was fighting with ONE ARM, YET HE KILLED THE ANIMAL PATH WHILE FIGHTING 6 BODIES AT ONCE. He evaded every single attack from the six paths of Pain, and are you not aware how beautifully Jiraiya was praised by Pain, a praise too beautifully given to overlook:
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