Roxy is tough as nails, you submit her (much easier said than done) or slam her head against the floor if you hope to finish her.
I see this going the same way Suarez vs Ansaroff went, only this time Barber is better on the feet than on the ground. Suarez couldn't do shit to Ansaroff on the ground, and she is this highly touted Olympic level wrestler. As soon as Nina got comfortable on the feet, she almost finished Tatiana.
Maycee might look good on the feet, but she's never faced someone as unorthodox as Roxane. Antonina Shevchenko couldn't pierce Roxy up, Barber won't do shit unless she goes balls to the wall and overwhelms Roxane on the opening 15 seconds. If it goes to the ground, Roxy probably wins based on control or even a sneaky submission.
Maycee might be strong and a savage, but she's careless and has poor technique. I'm going with Modafferi in this, and I mean it.