in this way you just add more items, but the problem will still... for example: if you go to miasma 90% of the times there is someone else farming, and 70% of those people will NOT accept to take turns. In this scenario, very often it ends in some lame player luring the rend and messing up the spawn to kill the others.Why I have been arguing the better point. There should be rare loot drops based on the number of players with rights. Things that only can be earned with 5+, 10+ and 15+ killers with rights. Solo all you want but without the numbers will never see those higher group drops.
If everyone can has full loot, there will never be luring monsters to kill players. In order to make the game fair and balanced, the full loot for everyone is the best option, then as I said the player damage scale based on the attackers number will provide the right challenge for everyone and is a win win
Adding more items based on the attacker number is nice but it just won't solve anything and will works only on bosses...