I'm using an a7sii, with 85 lens, and Ronin M.  I'm shooting two people wrestling.  I'm having all types of problems focusing because the wrestling is dynamic so there is a fair amount of movement.  Ultimately, the focus drifts off and then finds itself after a few seconds, but this severely compromises the film.  

 

My settings

 

F/2.8, shutter 100,  continuous focus, wide, face recognition on

 

 

If I was simply using the camera on its own, I would hold the shutter button until focus is reached and I could move around, but this is impossible with the Ronin because you are using both hands to hold the gimbal.  I don't have $2,000 for some follow focus attachment so what suggestions would you have for such a project?  

 

 

Another point is that face recognition is great when your subject is facing you directly, but in my scenario, I'm often shooting the tops/backs/sides of the faces, so the focus won't immediately recognize that its a face to focus on.  Should I switch to a wide lens like a 35?  Any suggestions?

I would turn the face recognition off and go with a smaller aperture to widen the depth of field and change to center focusing.