I think that in order to be able to seriously talk about the Fury - Usyk fight as a competitive one, it is necessary that Usyk gain at least a little weight (can he, given that he has already moved to a new weight category for himself?). Now Usyk weighs 100 kg, and Fury 123 (or already more) - 23 kilograms of difference, in fact, they are in different weight categories.
He will lose his speed and probably his accuracy if he gains more weight than he can afford, he is ok with his current weight as long as Usyk maintains that speed and accuracy, he can fight anybody as he did with Joshua and beat him, heavyweight is the only division where there is no maximum weight limit, Usyk if ever will add more weight it will not be more that will hinder his speed.
That's why Usyk is really a cruiserweight, and not a pure heavyweight. Fury is very different breed of heavyweight though and same with Wilder, taller and heavier. And it is not advisable for Usyk to put in more weight, yes he might lose his mobility and speed which is a big factor in his win against AJ. So it's better to just used the same weight against Fury (if they fought), but it will take a lot to be able to beat the version of this Fury.
There's only so much weight someone can put on before it becomes a hinderance as bodybuilders often don't make good fighters and are too bulky. Usyk obviously isn't a true heavyweight and I think he would struggle to get much bigger than he is right now but he should just do what he did against AJ and try outbox him and dodge whatever Fury throws at him. Easier said than done though and I think Fury is a better boxer than AJ.
We all know what Fury is capable of doing in the ring but now he has the added motivation of being a unified undisputed heavyweight champion if he can get past Wilder again and if can beat the winner of Joshua vs Usyk II. Even if Usyk defeated Joshua again then managed to put on weight, he will be no match for Fury.
Surely Fury is relishing the idea of fighting Usyk instead of Joshua for the belts too, since I would like to think there would be less risk of getting knock out, although I don't think it'll be any easier for Fury, however he'll probably get a kick out of fighting someone as technical as Usyk, since throughout his career he seems to the one with the better technical ability. I don't see how Joshua wins the rematch, Usyk moves his head constantly, and Joshua isn't exactly the most accurate with his big punches, and seems to struggle with fighters that are quick, and have good footwork.
AJ is just going to have to go all in and go for the knock out. He's not going to outbox him for sure. He doesn't have anything to lose at this point so he's going to have to do something drastically different if he wants to win. I don't think it's out of reach for AJ but he needs a new game plan.
This Fury fight against Wilder is going to be nerve wracking, I just have a feeling there's a potential banana skin here for Fury, he can't be caught napping otherwise he'll be literally napping on the canvas. I don't think it's going to go like round two vs Wilder, I actually think it'll be slightly more competitive like the first bout, though I personally had Fury winning that despite the late knock down.
That's what makes it exciting. Wilder could have that butthurt strength as I think Fury has got well and truly inside his head so I'm hoping he comes rushing out of the gates. I hope they're both just slogging at each other.