I don't know if you follow football (soccer) Riddick, but it reminds me of the Glazer family's takeover of Manchester United. Now I'm no expert and I could be talking nonsense, but it seemed to me how it was explained at the time, they didn't have the money but they managed to borrow what they needed to buy Man U using the football club as collateral for the loan ???
It's like Team Wilder don't have any money but they want to pay Joshua out of the money generated by the fight. I guess there is nothing wrong with that, Hearn has been saying 'make us an offer' so they have. It's what they were asking for too so hopefully they will take it.
They'll look bad if they don't for sure, although it is a gamble and a test of whether Hearn is as good a judge of the numbers as he says he is. Nobody really knows how much this fight is going to generate. By taking $50m it is conceivable that Joshua will be selling himself short and that Wilder will earn more than him.
This is unlikely though unless Hearn has been tactically downplaying what he expects the fight to make so as to lowball Wilder. Possibly more likely is that if Joshua is guaranteed $50m out of the profit (once all the costs are met) it is conceivable there may be little or nothing left for Deontay,
On balance though if I were Joshua I'd be happy to take a guaranteed $50m and if Wilder did end up with more than that then good luck to him.
It looks like we are getting a unification fight gentlemen.