In my other comment I mentioned that each one had a different topic focus: stats, epidemiology, soft skills, and even one brief coding interview. There was also a presentation I had to give that was to the whole group, so there was still a large- group portion. Most of the sessions had 2 people as well.

I think this way is less intimidating for the interviewee, saves time for the interviewers, and builds in some natural breaks. Having been on both sides, I prefer this to one 2hr+ session with all 8-10 people. This is especially true when the candidate gets a chance to ask questions, as they can see the different answers, and they might feel more comfortable asking something to a future collaborator but not a future boss.