For the outfit on the left, what about a short-sleeved tunic? It'd be more historically accurate, and you get to show off the arms? (Well, not necessarily historical for the Byzantines themselves, since they wore modest dress, but tunics in general, both long-sleeved and short, have been around forever.) You could go for a Roman armor sort of styling, which would mesh well visually with the rest of the outfit.

I want to use him in a comic someday but his chlamys in the second design is really hard to draw in different angles

Oooh, I think it would be good to use the first design as his usual attire, while the second is reserved for formal events like a gala or negotiation meeting ~