Can I replace / recreate a tri-fold garage door with three fiberglass flush doors?
If the existing setup works, I don't see any reason why it wouldn't work with new doors instead. One down side to this setup though, is that doors without jambs aren't that secure and could probably be kicked in fairly easily. If it were my garage, and I didn't want a standard fold up door or a roll-up, I'd probably put in 2 larger barn style doors, or if you have the space, one of those sliding barn style doors that has an overhead track to slide on.