I mean, Nathan Fillion would have been an amazing Nathan Drake if this movie would have been older Drake but it doesn't work with him playing the young version of him...
Tom Holland doesn't have the look ( too small ), and is, IMO also too young for the role. Even his voice feels wrong for the part. Not a good choice. And yes I'm thinking Nathan Fillion would have been a better choice as well. The little guy working Drake over in the fan film is Ernie Reyes Jr. Among other things, he was a Ninja Turtle ( Donatello ) in the original TMNT movie.
Pretty sure they're planning to have it as a prequel to the games, so it'd make sense to pick a younger actor, and just because Nathan Fillion looks like him doesn't really mean he's got the acting chops for the role either, his fan film wasn't bad, but I wouldn't call it good either... he's also not exactly a bankable actor, whereas Tom Holland is known worldwide thank to his role as Spider-Man, so that'll bring in the audience and make mo' monies, lol :P
Ahhhh! I see. Everything about this makes more sense then. I know Fillion is nowhere as big a star as Holland, and as you say, bankabilty of the lead is a huge consideration. I still think he has the "chops" though. :)