I think straight Jagd is all you need for varmit hunting. I hunted barns and holes for years for coon and badger. I grew up in ND and they had a lot of 40-50lb coon. never had 1 that could whip a set of Jagds. Only thing crossing to a bulldog will get you is a dog that is too big to get into the hole.
I kinda agree with you. I am pretty sure a Jagd or Patt can do the job without crossing them w the pit. Its just something I want to do, being a bulldog man at heart. And the pits I have are not the kind you are probably thinking about that are 80 lb big blue, bowlegged, jug headed pits. These are 100% game dogs and Ive got females anywhere from 32 lbs all the way down to 23 lbs. I have a quadruple bred bred Gr Ch Amboss gyp that weighs 23 lbs on the chain, 100 % bulldog. So the pups from this type of cross would not increase the size. I actualy have bulldogs that are smaller than some Jagds and Patterdales. But I do understand your point about being to small to go-to-ground.
I've had a few pits years ago that we're small I've always liked but I've never seen anything smaller then 30 lbs if you got any pics of your 23 lbs pit I would like to check it out.