You do realize that not all those dogs(if any) were pitts don’t you? At least half of them were mountain cur dogs or catahoulas or similar breeds. Traditionally that kind of hunting was done with cur dogs and catahoulas and florida blackface dogs. Only recently have pitts been introduced into that sport.
Btw, labs are now used as sled dogs. The most numerous breeds find their way into all sorts of things they don’t normally do simply because of their numbers. There are lots of pitts out there and lots of labs out there. Hence they get trained into fields they aren’t really meant for. I immagine pitts will soon find themselves being used as retrievers too.