This must be one of the most challenging roles to cast in modern CBMs.
This is basically an iconic role made even more iconic by Hugh Jackman's portrayal. So much so that the entire series became designed around him and he basically defines x-men now.
For the re-cast the following requirements will have to be met
1. Get a young actor. In late 20's or early 30's. To match Jackman's trajectory. Jackman started when he was 30/31. This age bracket will ensure a long innings for the actor as well as help with Point No. 4.
2. Involved Hugh in the casting process. Pay him a couple of millions to attend auditions and stuff and select candidates and slap on a Executive Producer credit on the re-cast actors first outing so that fans have confidence in his casting and so that he has the full endorsement of Jackman.
3. Be height agnostic. Jackman has owned the role that the role has basically become redefined. If a 6 foot 2 actor can play the role and be loved my fans and GA and comic book writers and everyone, proves that it is a needlessly limiting requirement which will rule out perfectly great candidates because of their tall height. So chuck the height requirement and be game for any height.
4. And lastly, the recast actor would literally have to become a bodybuilder. That's how Jackman has lived his life this past decade and he has said that his routine to prepare for his appearances as Wolverine are exactly the same as bodybuilders.
This is how Jackman looked in his last appearance as Wolverine at the age of 46.
Jackman has raised the bar again and again for a what a CBM physique can look like or should look like and above is the most cut most vascular an actor has ever got for a superhero role. It goes with the character and a physical representation of the rage inside him, makes him look like an animal Jackman said.
So the recast actor would have to be physically up to scratch. Comparisons would invariably follow with statements like if a 46 year old father of 2 A-list oscar nominee can get into such incredible shape, what's preventing a young around 30 year old actor.
The physical demands of this role are huge so (as stated in point 1) they should ideally get a young actor who can make the transformation and then remain this way for a decade.
I think Jackman has taken the physically to such extremes that I feel for the poor recast actor. Couple that with his fame and popularity and this is a very difficult role to cast and very challenging for any young actor to fill the shoes of Hugh Jackman.