The issue is Gina has never fought at 135 and been out of the game for awhile. Holly Holm would be my choice if they were going to bring someone in other than Cyborg, but Holly wants more money than the UFC has been willing to offer.
If it is Gina, she will get destroyed. If it is Holly, it could be interesting.
If it is Cyborg....it could be the end of Ronda