We had a terrier once that would not back down from a fight which sadly was her down fall with one of my lurchers,she went toe to toe as you put it, but when it came to earth work would not get close enough she didnt want to start scrapping with the fox below ground. some dogs will only get stuck in above ground , he might go to ground and end up a bayer not has hard as nails, Might not, but just my opinion, good luck with finding him the right home .
well said