Name the top 5 heavies then. we know 3

in no order Wilder joshua fury lets say klitscko retires, he's 41, he might have 2 more fights at most, he wont be around for long, who are the other 2 top heavies right now who could potentially beat the 3 listed or atleast challenge them. bellew is a cruiser, but there could be some cruisers who could move up. had to mention bellew, he seems to want to fight after beating a crippled haye. you can name up and coming fighters who will make the top 10 right now, but i mainly want 2 more fighters to make the top 5. tiger mohammed would beat up all of them 3 mentioned