I am fairly strict on my small group programs. I charge one third less than my single person rate per person in the group. I don’t let groups get bigger than 4 people. It could be more money, but the quality goes down. And they may as well just go to a big box gym or rec center with more than 4 people. Most of my groups are 2 people. But I don’t actively try to create groups. If people come to me looking to form a small group, I set it up. The particulars are worked out with each group.