Promoter of neither fighter wins Kubrat Pulev-Dillian Whyte purse bid

[Primo Carnera]

Anyone know the reason Pulev gets 3 times the payday that Whyte does when neither is a Champion?

Pulev - $1.125 million

Whyte - $375,000

Pulev is only ranked 2 places higher than Whyte but i'm guessing that's the reason?

I might be wrong, but I think Pulev was the mandatory for AJ through IBF and the fight was set , but he unfortunately got injured, so now he’s fit, he’s top of the IBF pile.
Whereas Whyte had been chasing the WBA Route, and it relatively new to the IBF pecking order.