A lot of them aren't trust worthy and worst of all they wanted the treasures for themselves. With a crew this powerful, it makes no sense that they lose. I think they dominated the battle field at one point, then got cocky and started fighting each other to get higher spoils.
They also said something like God Valley was their final battle, Big Mom doesn't seems to believe on Rocks plan, maybe the crew is at the brink of collapse, this battle will decide who gain the upper hand when they left the crew.
Whitebeard has no scars on his back, if anything he should be the last person to leave God Valley of the entire crew.
Big Mom probably got hands on all the treasures except the Paw Paw fruit, as what she said finder keepers, she isn't sharing the treasure including the one that Rocks wanted.
Kaido prolly went after Roger than after the treasure. Where did Kaido went? ran away or maybe captured by World Government while he was still new to his devil fruit power.