Usually we try and put coats on top of people's bags to try and make as much space for everyone as possible. Also drawing attention where possible to use the coat hooks provided, plus making full use of the wardrobe. Trying to help the crew put as much away as possible and playing overhead locker Jenga helps everyone to get away on time. I've never told anyone (or heard anyone be told) to put their coats on the floor but sometimes we have to do lots of shuffling to get away on time. It amazes me people would rather miss a slot and incur a potentially lengthy delay than have their bag rotated, moved across or maybe behind a row.