Black hats gonna do what black hats do. I would like the backstory as to when he would have been approached to conspire with the Becks. Those dudes could not possibly have invested effort towards such when Cowboy first arrived. They had good reason to believe JD would have been an ally in their fight against Rainwater.
I can see how a given man who was desperate to hang on as a cowboy/ranch hand would choose to go all in with Dutton. There just aren't all that many opportunities, especially for those with the assumed past of that guy. He also would have been impressed with how Rip and Kayce were all about doing a solid for the least of their hands, Jimmy.
As I was ruminating (I know...a dumb thing for Ol' Lonesome to do) about the Beth convo with Monica, I came to a realization that perhaps it was more in service to Beth gaining full control when JD passed. She has no problems with Jaime, at least for now. Kayce and Tate were absolutely going to get the ranch. If Beth could turn Kayce permanently against having anything to do with Yellowstone, Beth would get it by default.