That would be premature. Winner of Fury-Wilder vs AJ would tell us who is the #1. Nonetheless, if that fight didn't happen, then I would rank the winner of Fury-Wilder at top spot.
Beating a spent Fury? No. Beating any of AJ, Whyte, Parker, Ruiz, Hunter, Povetkin, Pulev and Usyk? Yes.
That's a fair point, and you are right the winner vs AJ would remove all doubt and declare an undisputed champion. That fight however would be the #1 in the division vs the #2 in my eyes, with the #1 being Fury/Wilder winner. I say this because no matter how you slice it, AJ got bullied and stopped within the last calendar year. There is a counterpoint however asking how anyone could put Wilder at #1 with that thin of a resume, but if he proves himself better than Fury he deserves it. Splitting hairs here, I just really hope the 3 of them all fight each other without controversy before the end of 2021. Hey I can dream right!!??
After reading this, I want it on record that I think neither Wilder, or Fury is the best heavyweight right now, so I’m no way does the winner have any claim to being the champion. Joshua has fought far better opponents than both of them, and is the heavyweight champion until someone beats him. Andy did and was the champion for a short period, Fury, Wilder or any other boxer has to do the same. Wilder is getting the credit he deserves right now, his level of opponent has greatly increased since he fought Ortiz. Fury on the other hand had fought embarrassingly poor opponents since his comeback, yes he beat Wilder the first time round, but apart from that it has been terrible.