Do you mean smoothing groups or like…turbosmoothing? You don’t want to try and turbosmooth the models since they’d end up looking like lumpy turds.
As far as I know, 98% of the models you extract from Crysis need to be resmoothed because the smoothing groups come out messed up (every face shares the same group). Also, if you’re porting the 3rd person models, then expect them to be low poly. You can’t really port the first person models if you intend on using them for posing and whatnot since they have missing faces for optimization purposes.
But if it’s to make SWEPS or weapon skins, then definitely get the first person models.