Hi lurchergrrl
As most people hunt in diferent ways and require different attributes and skills from their hunting dogs, the choise of bushing dog should suit their needs.
Yes, there will be good bushing/hunting dogs from many many differing breeds and crosses. But there are dogs that are made for the job. And for me, I wouldnt chance it on, say, a collie/terrier, when I could have a spaniel/terrier, bred from cracking parents.
Spaniels are crackers for close range flushing, and are easily trained to hunt away within 40 yards of you, they wont miss much.
Terriers are a bit headstrong,