Trading with Louis is a seriously bad idea. You only have to let him through once and you can be screwed even with a good chin. Let him get on the inside and you are gone. If Holmes wants to win this fight he better enter it on the asumption that he is not going to trade with Louis if he can humanly help it.
It's not like Larry would stand in front and go toe to toe with him like he did with Norton in the 15th. I'm talking maybe 5-10 punch exchanges, tops.
A couple of years prior, when Coetzee had no title and was worth just normal money Holmes said something very close to "i'm not fighting that goddamn South African". He hammered the **** out of his country and was in no small way never going to fight him. When it was worth HUGE money he had a sudden change of heart on Apartheid.
Holmes could always be bought over to some extent. He wouldn't be bribed to lose, but he would fight King Kong on top of the Empire State Building if he was payed enough. He was a buisness man, not the typical buisness-dumb fighter. The only guy he would have fought for little money was Foreman.