Not really based on extreme physical likeness or anything. I just think Cartwright is a very talented actor who should be in more stuff and he has the chops and is roughly the right age to play a good Orpheus
Mary, Canada, 715, Queer: moderately firm grunge, Game of Thrones, Marina and the Diamonds, all things Joss Whedon, Jessica Chastain, The Sandman, Community, Hannibal, Spartacus, and me making dickish comments on pretty much everything. Oh and Tom Hardy. There's a lot of him in here too.
I also did a Sandman Casting a while back which you should check out