Better yet. Allow players to create public game that are either public loot or personal loot.
No. If there is a certain X% drop chance in a 8 player game, then simply make the personal loot drop (X/8)%. The total amount of drops are unaffected.
In relation to the trade economy, I have shown why personal loot promotes a more robust trade economy in comparison to global loot. It also, discourages leeching and autoclicker cheaters. Pease see this link for the math and simple logic.
D2R: Personal Loot is a MUST for this game! - General Discussion - Diablo 3 Forums (blizzard.com)