I probably am not a good person to respond because of the numbers we have. We have over 50 minis and ponies.
First, we have never stalled our horses 24/7, even when we had only a few horses (way back when)
Yes, we have drylots and we have a full pasture, and we have some small pastures with short grass in them. We try to rotate our different groups throughout the grass-growing season so that everyone gets time "nibbling". And we feed hay to everyone, unless they are on the full pasture. The amount is obviously increased if they are on full drylot.
What has worked for us when feeding in our drylot areas is placing rubber mats out. And spreading the hay on the mats. Then, if the group is being grained, we place their scoops of grain on top of their hay piles.
We also have a number of large rubber feed dishes that we use for grain, but they tend to live in the drylot just off our barn.........