We did but you Tsunade fans think she can regenerate from anything in a few seconds.
Not even close, you apparently just don't know how to interpret manga. Tsunade said he's no ordinary medic ninja, applying to his use of the chakra scalpel. However, Tsunade had performed no medical ninjutsu at the point that Kabuto said she's no ordinary person. HE then goes on to talk about how an ordinary person wouldn't be able to move, indicating he is obviously discussing durability.
All your attempting to do here is downplay Tsunade. But she obviously has more than slightly above average human durability given she didn't activate her seal until she arrived to the battlefield. Whereas, those with average human durability died before reaching the battlefield, cut to pieces. As opposed to what Tsunade referred to as minor injuries. You're simply prejudiced against Tsunade and you're doing your best to try and downplay her feats. IT's ok, but let's not pass of fancfiction as cannon.
Um Tsunade grew up in an age of war, let's not forget that when people were far more power than this now, and she has a crapton more experience that Sasuke. But even assuming she didn't, the fact remains, that Tsunade was able to coordinate attacks with a V2 Ay, which I don't think is possible if you can't see them. Further Bee, who has no doujutsu was able to keep up with V1 Ay no problem no just visibly but physically as well. The fact that Sasuke was overwhelmed isn't proof that everyone would be overwhelmed, because all of the gokage, gaara, excluded performed combos with Ay. And people beyond the precious Uchiha have been able to see him.
You literally have no validation for that claim, you just made it up on the spot. You don't know how much Tsunade has left in her lifespan. It takes less chakra to heal something back together than to grow a whole new one. There's no real reason on should regrow something if they have the means of putting it back together. Tsunade states that normal healing of the mystical palm sort takes a lot of chakra. Why would she waste chakra growing a lower half, when she is able to use her remaining chakra to follow her nindo as a medical ninja.
That's just a bad example, because the speed of light would rip a person a part, and destroy bones, as per the cutting force of the wind. When someone travels the speed of light, what they would show as would essentially be ribbons of who they were. The damage that would be dealt is on a completely different scale than what sixth gate guy can push out. Especially considering directly after the attack Kisame's clone still looked to be alive. She not only has durability she has a contingency plan of healing, which realistically Gai can't overcome.