I personally believe that if targeting system was implemented (which it probably will not), then it would only make sense to decrease the amount of ever increasing girls with AOE skills. From my perspective, most high tier girls have AOE skills except maybe for the ones geared towards more 1v1 raid bosses; with counter, dodge, life drain, etc. So if targeting system was included, they might as well make most girls single target like in Osawari Island with only a few of them with an AOE proc. Because technically large area skills will not be as necessary as you can pick out who to target.