cat or bmc with pit can be good as long as the dogs are bred to hunt and not to just work cattle...
Reuben, curious as to why you have this thinking about the "cow dog" blood. Why would dogs bred for cow work not hunt? In my opinion, and experience, the job description and working ability of a cow bred cur type dog is at a much higher level than the average hog dog. And they should have all the hunt of a hog dog.
On the topic at hand, I tried this type of cross years ago, Catahoula, Plott, Pit, bred and selected for four or five generations. I produced many nice dogs and one outstanding female that is still alive and with a friend, but I culled the whole line except for her. Lack of holding style and dog aggression that showed up at 4-5 yrs old. I stuck with the straight proven cow dogs and never looked back other than to keep a few 1/2 or 1/4 Plott dogs for when I dont have to work the next day.
