MixChamp was conceived as a successor to tf2mix, a similar mix PUG system. It was also created as a pug system that is friendly to players that are new to pugs and PugChamp.
After developing PugChamp, we realized that there were a few barriers to entry in a high level pug system. We decided to remove captains and auto-generate teams to have quick, accessible pugs for all players of any skill level. Currently, MixChamp is in Alpha and will be developed alongside PugChamp.