What's the minimum and maximum group size for a faculty-led trip?

“We run faculty-led groups from 8 students up to 40+. Below 8, we recommend students join one of our open-enrolment volunteer or medical internship programmes instead. Above 40, we split the cohort across parallel programmes with shared briefings and excursions. Most successful faculty-led groups land at 12–20 students — large enough for cost efficiency, small enough to deliver real depth.”