One solution for multiplayer would be the host rolls the abilities, and everyone has access to the same pool, so you don't have multiple 18's for some, and nothing higher than a 13 for others.
This would of course be standard 5e rules, where you roll 4d6, dropping the lowest each time, and doing that 6 times, and players get to freely assign the scores where they want. Not "roll 3d6, in order".
