In mixchamp, players are drafted using the system of hidden ELO (meaning ELO the players cannot see). Teams are balanced without the need for captains.
In pugchamp, captains pick the teams. ELO only affects the players after the pug is over; it has no effect on the draft.
SkyeELO can represent a player in a matchmaking setting, but in pugs, players are cherry-picked by captains. Players are not being matched up against the entire pool of puggers - they are selectively adding up to pugs of different skill levels, and being picked by captains of different skill levels. Captains already split up the skill level of players.
SkyeThe TF2 community is small enough that most players know each other – this is especially true on a pug website with a small pool of similarly skilled players. Good captains have knowledge of the players they want to pick. They know the skill division of each player, and the class they main. They know who the trolls are and the players who won’t play their mains seriously. Thus, captains generally disregard ELO in their picking process.
Any of the issues I highlighted here and in post#196 wouldn't exist with hidden ELO.