Coria's 6 ft tall. From his highlight video on Youtube, he looks comfortable playing wide on the right if need be. I think MrSangster left Alston out because his status is up in the air right now (injury + discipline).
YOU CAN NOT PLAY ALSTON AND DOMI IN A THREE MAN BACKLINE! That is crazy. They are full backs. Their skill set is such that they are expected to make forward runs and pass the ball. A member of three man backline needs to have positional sense, be good in the air and tackle. People do this crap all the time on BigSoccer. Just because a guy plays soccer on the Revs doesn't mean you can just slot him in at any old position.
Alston was a left back for 3 years in college, now he is a right back. heaps was a midfielder, then a right back, then a left back. Albright a forward and then a right back. Players with athletic ability can change or adapt. Never seen Domi play so i don't know what he is capable of but I am sure Alston can handle it as he is a much better player than heaps how played right back in a 3-5-2. If you are playing a 3-5-2 with 2 defensive mids it should not be a problem. Just because a guy plays one position does not mean he has to be pigeon holed into that position. if alston and Domin are a good enough soccer players and athletes they could transition into it.