Yeah, but it's mostly a combination of "full intel", and the misconception that frog song/entering sage mode actually takes a long time. Plus the misconception that boss summons are weak and get fodderized and are removed from the fight automatically by any jutsu, when in reality they're completely separate characters and can play huge(lol) factors. Same for the idea that Base Jiraiya is somehow completely worthless but we saw how that went already.
Then on top of that, there's everything that the manga emphasized to this point that supports it, assuming people aren't oblivious of what's been clearly shown thus far. Then we have one of the most versatile arsenals in the manga, most experienced characters and obviously a bunch more reasons than just this, but it's what it boils down to essentially.
Also since you made the thread, is there a specific reason you reacted like that, what do you think of the matchup?