This was my experience, too. The groups were rotated, so that a different group disembarked first at each landing place. But other than the time you disembarked, there was no control over how long you spent ashore.

I suspect, though, that our selection of landing places was also limited by the numbers involved.

Nevertheless, the Marco Polo is a lovely and friendly ship in addition to her sea-keeping qualities, and I paid a great deal less for my week on board her than I would have had to on the expedition cruises - whether the "hard" experience of an icebreaker or the "soft" luxury of an A&K-type ship.