Super Smash Bros. 4 Model Project

[Random Talking Bush]

Doubled up meshes
Most likely so that it could be rendered on the inside in game.

In particular, the duplicate of the mesh is for the backfacing, basically polygons that would only show up on the opposite side instead of being one-way like most models are. Many models with cloth tend to have that, especially if the texturing is different for the opposite side.

More often than not you'll need to work on splitting those polygons into two separate smoothing groups for it to look proper. Deleting the one side could cause more problems than it'd fix for certain models.