Before i start, plz dont give me that bs and tell me what they said in part1. Neither him or itachi were shaking in fear when they finally met jiraiya and infact, kisame held of jiraiya with confidence for itachi to beat the crap out of sasuke.
Anyway jiraiya uses oil and fire techniques and against a ninja that can create an ocean, jiraiya's tech isnt working. He would need sage mode, the question is will kisame give jiraiya that much time to go into sage mode.
Also take into consideration that kisame fuses with samahada alot faster than jiraiya can get into sage mode, but also he is alot stronger and faster when he fuses with his sword