Zuffa Boxing seemed to be taking a larger cut than the UFC based on the brokering of the fight through Zuffa Boxing LLC, but nobody will ever know who the partners were for sure. Lorenzo was heavily involved in making that fight happen. So, my impression was Dana White fucked the UFC on that deal. Dana has business interests outside of the UFC now with the birth of Zuffa Boxing LLC which was likely a co-promoter of the Floyd-Mac Promotions card.
Dana's allegiance is no longer 100% to the UFC.
Guaranteed 40M is out of the question on a Pacman fight. His Floyd guaranteed money was only 20M-25M if I'm remembering correctly before backend.
I'd say Pacman is a guaranteed 10M. More than the UFC is willing to put up right now for his next defense.
Paulie is a better matchup but doesn't have the name value needed to sell a freakshow.