Many weapon that are twins or just another version of them that maybe got modernized, futurized etc.
Example: M4, M4LMG, XM4
AK47, RUS, AK117, KN44
Why wont we just merge them into one singular weapon, then if you want to change something just equip another different attachment and mods into different type of them.
And the skins, depends the weapon type that you made.