Hunting and Terriers

I was recently asked a question about the social behavior of working/hunting terriers and I realized that I had never seen the answer anywhere (even after a week of research!). On this website and from other resources everyone talks about the social behaviour of JRT's in the home and kennel and we all know that two dogs of the same sex should not be left together and that there maybe underlying issues with jacks and dogs of other breeds (both good and bad). However, one issue not addressed either in the history of the breed or in social forums is whether or not the Jack Russell was used to hunt in packs, groups of two or three, or a singular hunter.

For example, what was their role in the "fox hunt?" (from beginning to end)

Is the Jack Russell primarily a pack hunter or solitary hunter? I can guess from the day to interactions of terriers and what I've read about their home social lives that they probably hunt best in groups of 1 to 3.

Does anyone have any resources on the original hunting/working events in which the JRT was used that would help to answer these questions? Any resources on the current use of the Jack Russell as a hunter and working dog-not in competition?