One of the Raikages blitzes Tsunade and chops her head off. Team Sannin is screwed. They can't protect her and fight the same time. And the toads aren't much help. One punch from a Raikage can KO them.
One can't do that.
Yes they can. Shadow clones. That's the point of shadow clones, as added backup to team mates in case of blitzing. But, incase you forgot, tsunade doesn't need to sit around and heal. That's why katsuya is on her, it transfers her chakra over to team mates.
True one punch from him can do that, but the toads are able to move around. Raikage has to catch toads which are able to jump far higher than he can, and gamabunta who is able to use water bullets to put him on a somewhat defence. In the first place, what defence do team 1 even have against mud swamp? That right there puts them on a bit of defence as they have to get out of that while jiraiya sits with tsunade and 4+ shadow clones in a sensing barrier.
Your mistake is that you assume team 2 has to engage in taijutsu with team 1, when the truth is that they can sit far back and spam long ranged jutsu. Team 1 will be seen starting their blitz a mile away.
Earth, fire, wind(orochimaru has shown at least 1 wind jutsu, so he possibly has more.) jutsu and oil will put a stop to team 1.
Team 1 is a team of 3 taijutsu fighters and 1 mid rangedfighter (darui), while team 2 is a team of 2 immortals, a medic, 1 taijutsu fighter(tsunade) and 3 mid-long ranged fighters + massive summonings.
*when i say taijutsu fighter, i mean primarily taijutsu.
Though Bee has samehade to suck up chakra from some of the large scale attacks, the attack would still be enough to put team 1 on the Defence.
