Dougray Scott As Wolverine In "X-Men", Replaced By Hugh Jackman
The Wolverine we know and love today is usually the one portrayed by Jackman, but Dougray Scott, who was already pretty well-known in 1999, was slated to play the gruff hero. Hugh Jackman got the part when Scott's other movie took longer than expected to finish, and the rest, as they say, is history.
Also, how would anyone be able to tell when some background character in GoT was replaced? There were a ton of them, and they all looked the same.