Let's clear some things.

Cesaro. Heyman was paired with Cesaro because they wanted to find an excuse to keep Paul on TV to spam the 21-1 deal. Cesaro was a means to, not the focus.

Axel and Ryback. Axel and Ryback were paired with Heyman only because they wanted somebody to feud with CM Punk when Brock wouldn't be there. Axel didn't work, so they added Ryback to the mix.

Which means that these guys were never Paul Heyman's priority. That's why they didn't work. With Rousey it could be a different deal, because she would be Paul Heyman's priority and not a means to push Paul's other client. Because Cesaro, Axel and Ryback were used in order to push Brock Lesnar and CM Punk. So Heyman and Rousey can work.

However, I also don't think it's needed. Rousey has shown a very human aspect and character. A very humble character. Paul Heyman's client CAN'T be humble.

So, she doesn't need him nor will her character benefit.

Other people need Paul Heyman more. Finn Balor and The Club for example.