Not a issue I have had to deal with. Walking in a large group I'm very happy to mingle and let someone else do the thinking. But If I have gone to the trouble of planning a walk and lead it, then I expect other participants to respect my desirous as long, as they are reasonable. People will always try to help out, as they see it. The trick is to go with the flow, but be clear that you are leading and it's not a comitee meeting.
I recall being asked to lead a walk at short notice, in an area I had not waked before. I arrived early and actually drove the first few miles and recede the footpath off the road up on to the moor. At the brief I joked that I had no idea where we were headed but assured everyone I would get them home for supper. The trick then, was to confidently lead the group off in the right direction and up on to the moor, as if I lived down the lane. During the walk I soon worked out who had local knowledge and used a few simple jestures here and there to check they were happy we where taking the right gate and such like. There was one minor mutiny that few spotted. I kind of forgot lunch as I hadn't planned the route. A couple of the ladies asked where we were stopping. I suggested a tor a mile or so further on and they basically stopped where we were. Quick as a flash I anounced this was the lunch spot. Turns out where I had in mind was windy and I made a point of thanking the two mutineers. Any way hope you find that tale usefull., Or at least amusing.