Well, if it’s anything like other games I’ve played; the player with the highest amount of perk points into it would override anyone else’s Charismatic Nature. The other way it could go, looking at you Diablo II, is that the last person to get in range of you has their affects applied regardless of whether or not who has more perk points invested in it.
Stacking would be a bit more difficult to code, and if not coded right, will cause some serious lag. It can be done though.
