It's safe to say that UFC fighters due to their already established presence in the combat world.
There are several UFC fighters who should jump to WWE.
Donald Cerrone has had an incredible mixed martial arts career. The UFC veteran is a true veteran of the sport and will go down as one of the greatest UFC fighters of all time.
With such a personality and a record that speaks violence, Cerrone could be a great addition to WWE programming.
It doesn't get more dominant than Francis Ngannou. If Ngannou can learn the craft, he would be a huge asset for the WWE.
Conor McGregor is a fit everywhere. The Notorious gimmick works wonders. McGregor and WWE have been linked several times in the past, however, nothing has materialized.
Be that as it may, it won't be surprising to see Conor McGregor inside the WWE ring years down the line.