It could work but doesn't sound that fun, furthermore turn based RPGs can be very boring and it is very rare that someone will actualy play your whole game (unless it is very good or has great art) as there are hundreds of mediocre rpg maker games on the Internet and your game will probably be quite long and require lots of time investment from the player. Another problem with this is that it wouldn't feel like you won the battle, rather it would feel as though it was down to chance, but it could work.
Cool idea but I think it is best to stay away from full RPGs as there are so many of them out there