This was one of the reasons I suggested system defenses, to provide some more variety in the fights.  My guess is they will use the same "champion" combat system as the original game, and have all the fights be 1v1 (and maybe some 1v2-3s) where the concept is that each fleet is represented by a "champion" to resolve the fight.  It's an abstract way of resolving a fleet battle without having to deal with 12 (or however many) ships per side.  One of the thing system defenses would do is break up the monotony that can be associated with this system (like fighting the 10 Umgah's in a row in SC2) by providing more variety in the way that you represent what are supposed to be larger battles.