This mod gives Jungle SWAT and Desert SWAT restores what Rockstar only hinted   a true separation between SWAT, Jungle SWAT and Desert SWAT.

Each SWAT are only appear in LS, SF, LV but Jungle SWAT only appear in Countryside while Desert SWAT only appear in Desert.

Put "Jungle SWAT and Desert SWAT" into Modloader

You need Model Variations :
https://gtaforums.com/topic/977777-model-variations/

Credits :
NikoEntertainment - Photoshop edit
Shaman123 - for making Woodland Camo SWAT and Desert Camo SWAT
cjfan_ - for Model Variations