I find the bigger the space the cleaner they are in sheds. I have six dexters staying with me and they need about a round bale a week, they are on hay in a ring feeder so the dung is quite solid and they are very clean and lie down a lot.
We have a small dexter tractor and at the end of the winter, all the muck is shoved out and we get a grab away lorry to take it a way. I just have to do the corners by fork and barrow. I can not stand waiting for a farmer to turn up as and when, the grab company does muck professionally within a day.
I also deep litter ponies in another shed, the manure drops and compacts over the winter, so its never that deep. I get through a round bale of straw every two weeks, with five ponies.