You have to know how to nudge without upsetting people. If the guy in front of you becomes stationary, very very slightly bumping into him, as if you were simply continuing to walk — as expected, since the circle should be continuously moving — should not set off any fire bells.
If the shul is big enough, you can make multiple rings of circles. If the shul is not very big, those walking in a circle directly around the Bima slows down the other circle(s), and so usually such a circle (or even individuals) directly around the Bima should not be occurring in a non-large shul.