User blog comment:CheeseBurgerGuy/Ridonculous Race: Teams That Could Have Been (Season 2 Theory)/@comment-455481-20190822012539/@comment-35606925-20190822024347

I believe it would most likely be 6 returning teams, 6 teams that are semi new but with at least one contestant from TD and RR, and 6 completely new teams. I do also think the split down the middle makes sense as well though.