A group of cleaners are sweeping up animal feces from the street during a parade or festival.
A man walking on water.
A group cannot be a man simultaneously nor can one be walking on water and sweeping up animal feces simultaneously.
A group of cleaners is more than one man, and while the man is walking on water, the cleaners are sweeping up animal feces.
You cannot have both a group and a singular man.  They cannot be sweeping at the same time as walking.  They cannot be on the street at the same time they are on water.