There's Catahoulas like that out there, whole lines of em that produces the same type of dogs as the Yeller dogs you talk about. If you've got a high producing line, stick with it, but there rare. They may all bark at a pig and find there own hogs young and make decent dogs, all of them, and that's alot of good right there, but that don't make em a hog dog in my book.
If the yeller dogs are more accessible to you, well that's what I'd hunt, same goes for Catahoulas. It's took me alot of culling and alot of miles to get where I'm at. I've got one dog over 3 and one over a year and some pups, ALL virtually a different breed. I've started over and culled just about everything more then once. I don't care ably starting from square one again, because if I'm not satisfied then I won't feed em whether that means I won't catch another pig for a year, so be it. That's all I'm saying. Plenty of dogs find pigs, but that dont mean there a hog dog.
I bought and culled from both of these breeds and never really found what I liked...seems the cull rate was real high for some of these dogs back then...and I saw lots of these dogs go through the woods and just keep on trucking and someone else come right behind with their pack of dogs and they open a few times on top of the other dogs tracks and bam...hogs running everywhere...but as many people that like the yellows and the cats I am sure there are more good lines out there than ever before...I always say I like a dog that knows how to find a hog if it is there...I have seen some dogs that stay busy but don't find many hogs...friend of mine calls them brush beaters...another friend of mine has a nice looking bmc pup that is coming on and he has 1/4 plott...I am sure the cull rate can run higher in some breeds...more so than others....