If your friend picks up something you need he NEEDS to give it to you. If he outdated a piece of equipment you need, he NEEDS to give it to you. If you need a spell from the shop and only he has money he NEEDS to buy it for you.
So here is when communication and negociations come in play. And if your "friend" is being a dick about it, there's nothing the devs can do.
Congratulations you created two systems to fix a problem that doesn't address the actual problem, it actually makes things worse because now they can say they own it... rather then them being in possession of it.
Well I don't know of any system that would make a shitty person be less shitty. At least with roll/instanciated loot, you're garanteed that it's not the fastest looter who takes all.
