That's exactly right.

Sounds like some sort of group activity - ? On a team day or something like any trainers hired for the day can do more with the group if it is relatively small, a lower person to facilitator ratio means more different activities can be accomplished in a day. That’s the meaning here, there are various ways you could phrase it; ‘We can cover more ground in a single day with a smaller group’ ‘With a max of 11 people we can complete every planned activity’ ‘Small groups mean less time spent on explaining and managing the group, so we get more done in a day’ And so on.

Yes, that's probably what it means, but you should add what the activity is.