There is a mingebag playermodel mod that works with zeta players. If you want zeta players to look like mingebags here you go

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2102951114

In regards to them battling Idk just make two zeta teams and make one team explicitly use this model. I don't personally care about mingebags but thought i'd share since there's more then one post on this.