How does the Aum-Warren co-promotion of Fury works?

Looking at the Fury-Joshua drama, I am just wondering how does the Arum-Warren co-promotion work for Tyson Fury? Could it be the reason Arum is not so enthusiastic about the Fury-Joshua fight? If the fight is not happening in the US, does Arum stands to lose out on some of the potential cash split? I believe Fury-Joshua would be considered an all-British fight so what would be the percentage split of the promoters and how would Arum-Warren split that money? Normally, boxing fans see any fight as between Fury and Joshua and their willingness, but a lot of that is down to promoters and broadcasters. Fury has a contract with ESPN but how does that work? Does ESPN give Fury the said amount besides his earnings? make it a base pay and deduce it from the overall earnings if it is higher? While much of those contracts are not public, but what do we know?