I've not seen him play as an advanced winger before but if you assess all his attributes in comparison to Pepe,he's got the speed as well along with crossing and dribbling attributes..Isla might not be the most fashionable option at RW but i think it could prove effective enough in my opinion.I've seen Isla beat his man many times before when he played as a WB for them.
I've seen Wingbacks make a smooth transition to wingers before ,i dont think it should be hard enough for a versatile player like Isla.He possesses the required skillsets to play at RW imo.
Isla-Licht combo down the right could work great.