Seeing the weapon problem... I offer the view of maybe setting a hard cap on how many "weapon" items can be in a backpack as a rough solution.
Realistically speaking, carrying many MP7s is possible, not very convenient and if they are loaded, kinda dangerous, but maybe if we just did that cap to say, 2 or 3 firearms (Per backpack or maybe in total for an inventory, which could be 4), maybe there is not going to be so much hoarding, if that is really a problem.
Still, if we get too many weapons in circulation in a hypotetical case, we could just trade them with other groups/players, that one is not much of a concern.
Also, seeing people carry an entire arsenal is hilarious and kinda strange (Have done that before lmao). Though, I guess you take that for granted for that question to be made, somehow.