My own opinion on the subject is that if you want to surround small coverts with lurchers and guns then mongerals bred for the job will do. If one of them is or learns to mark then better still.
If you want to surround big coverts then IMO you need hounds and as many as you can use. But quality is more important than quantity. But big coverts to be surrounded efficiently need a lot of lads and foxes will get by and then that's where you need a man who needs to know hounds.
If you're talking about proper hunting where you hope to use hounds to find, hunt and hopefully mark or account for a fo