The Gun Mettle update introduced "skins", weapons that have the same model as stock weapons but with an exterior finish and wear. Those belong in skin banking because that's what skin banking sells and buys. Those don't belong in the weapon bots as it will make it quite cluttered. The Invasion update did not release any "skins", weapons like the C.A.P.P.E.R. from these cases are reskins that belong in the weapons category, because they don't have the same model as the pistol, nor a specific exterior finish with wear. They also don't come from a case that has only "skins", like the Pyroland case or the Powerhouse case.