Well, I am not an expert as we have only cruised twice so far. Both times we were included in a group of 40-50. Families and friends, but not all connected. We used a long-time TA of one in the group.
The TA made sure we were all along the same corridors, same dining time, and all grouped in the same area during dining. Same hotel, same flights, same shuttles.
Not sure how, as individuals, would have coordinated all this???? Thanks to this very special TA, who via email, took care of everything. It is a shame she is now retired.