[ NIHON BUNKA KENKYUU ] BUNKEN 101: Reviews, comments, and insights on Japanese pop culture.
Coming from the expereinces and observations of a long-time cosplay event organizer -- quality-wise, team cosplay is a better alternative to group cosplay.
Let's get some definitions out of the way first: group cosplay is, as the name implies, a group of cosplayers competing against other groups. On the other hand, team cosplay is a team of constructors working on a single cosplay entry, which will be entered in the individual category of the competition (if at all).
The obvious advantage of the latter versus the former will be felt in the resource pool. time, effort, and expenses for a single costume divided amongst three or four constructors will pan out better than a number of costumes done individually by group cosplayers. Participants in a team cosplay need not skimp on raw materials nor rush the construction of parts, unlike group cosplayers who will have to make everything individually, and then hope that the other members of the group are doing their best as well.
Since cosplay teams only construct one costume and compete in the individual category, there is also no pressure for them to rehearse for skits -- it is generally not part of the criteria for individual cosplay. Meanwhile, on top of costume construction, group cosplayers also have to write scripts and edit music and make time for rehearsals if they want to do well in their category.
Last but not least, group cosplayers are at the mercy of the crowd and the judges perceptions. For the crowd, the group cosplay effort will almost always fall short of their expectations, simply because they had one or two members of the ensemble missing (imagine an FFXII group cosplay without BALTHIER or BASCHE).
Cosplay groups also suffer at the hands of judges, who will count poorly-constructed costumes as a deduction in points for the entire group. And at the other end of the exhibition hall, a single phenomenal effort by a cosplay team is drawing raves from the judges and the audience alike -- earning both the admiration and the scorn of demoralized fellow cosplay competitors in the category.
From a statistical standpoint, there are too many factors to consider if you want to put together a group cosplay that's designed to win competitions. Someone in the group will inevitably screw it up for the rest. So, if you are a cosplay purist who wants complete accuracy in costume costruction, or are simply a design and construction team set to blow your competition out of the water, then team cosplay is the way to go.