The animal path is a very potent and deadly ability/body that Pein uses. It did give Jiraiya a decent amount of trouble and the path is most likely around a high jounin skill level.
With that being said, I believe that the Animal Path could do a decent amount of harm to all of the Sannin and give them trouble. He would force all three Sannin to use great power in taking down his summons and the path itself.
Though, I believe you know why he is so deadly here is because of his location. An urban environment where he can hide and continue to spawn more creatures, and hopefully box his enemies in is the ideal location for the Animal Path. Jiraiya can deal with the Animal Path, mid diff. As was shown. Tsunade would have a significantly harder time because of the fact she lacks any real long range attacks. And Katsuyu's slug acid would most likely already be used or spammed as much as possible to defeat the Dog Summons.
So, Tsunade would win this High diff. The location and the nature of the Animal Path would just be more of an annoyance for her. She would just need a window or chance to get to him. And when she does, the fight could potentially end. I say that because the chameleon was shown to be somewhat fast. This could allow it to evade an oncoming Tsunade.
But, in the end I feel like she would eventually deal with a majority of the summons. Katsuyu would be stuck perma-spamming the Dog Summon with Acid in the end. Tsunade high diff.
Orochimaru has the hardest time here. His lack of jutsu and the terrain itself does not help him out. I'd say that he can most likely handle the path with Manda and his army of smaller summons. Manda would be used to restrict any enemy summon coming his way; Then Orochimaru can either summon the Three Headed Snake to help him out or transform into the Yamata No Orochi state.
Once in this state, he becomes a bigger target. But at the same time he can defeat any individual summon. The key note here is that a few could come at him and rip away at him. Though, in the end I see the snake heads tangling around the Chameleon and Kusunagi piercing the skin and eventually cutting away at the Animal Path itself. High diff for Orochimaru.
