I said the other day that it would make sense to have Jade and Nia compete for the U.S. title because it would give Giulia more screen time and it would help legitimize the belt. Just copy what RAW is doing with Becky by having Giulia face everybody, whether it's legends, veterans, or up-and-comers.
But then you remember that Tiffany's beaten Jade and Nia clean multiple times this year. It comes off like they're only competing for the midcard title because WWE doesn't want them to be world champion, especially Jade. Like Roman said, it's the loser bracket title and since Tiffany beat both contenders, that makes them her number twos.