They may not have a huge amount of space but set ups like this (and variants on it) are a better compromise than stabling by a long way. They have some freedom to move around - considerably more than in a stable - and the freedom to interact with other horses.
Can totally sympathise, our yard is on heavy clay too and the fields are virtually unusable in winter. Ours go out in pairs for 2-3 hours each day either on the turnout area with hay and access to a bit of paddock, the rest of the time they go on the horsewalker, loose in the arena 2 or so times a day. They cope pretty well, they love their stables! The mud is so deep it’s pretty hazardous, we also worry about tendon injuries, mud fever etc.
I used to be one of those people that preferred individual turnout until I got my mare last year who point blank would not go in the field without a friend, she is now paired with my other horse and after a bit of back and forth working out field dynamics between them I would not go back to separate turn out!
These are brilliant!!
This is what we have for our liveries. We try and keep horses in fields as long as the weather holds.
But southern ireland is very wet. The horses actually love these pens, they go out 7am til5/6pm or whenever they start shouting for their dinner and beds!
I don't think things have moved on much for stallions. I know several that never get to run in a field.
An acquaintance doesn't turn out at all during the winter as she doesn't want to deal with mud. She has plenty of land and is obsessed about having grass all year, which she does have, but only because her horses are stood in stables looking at it. They go out for a few hours in summer because she says leaving them out makes them too tired to ride. I haven't the heart to tell her that's not tired, it's contentment, instead of the coiled springs she usually has.
personally I think it's cruel.
) we need to get more creative with how we keep horses. They don't HAVE to be on big grassy fields. You could make more use of less land with surfaces tracks that wouldn't turn to mud but that would require a lot of investment and drastic changes to our planning in the UK. I have seen some gorgeous tracks in the Nederland's with trees, hedges, shelters and herb planting that looks a lot more horse friendly but doesn't take up 'that' much space. Although being social media it's probably not real. You'd think planning would prefer that of mud baths with sunken haylage bales and ugly electric fencing 
would potentially be better for biodiversity as well. I just don't see it. Being very realistic which is sad.
A friend has recently found a fabulous track system for her metabolic retiree. They've made use of an existing old track by a canal (well fenced off obviously), have some grass areas, some hardcore and a large barn. Its not entirely grass free because there are weedy bits, hedgerows, banks etc. Its not the sterile track you see at many of the track liveries. Its what I would build for myself if funds were unlimited and planning laws less prohibitive. I'd wind it round the perimeter of my fields with gates into the fields at various points.I do think with less land, more rain (and fatter horses
my dream grazing is a couple of hundred acres of saddleworth moor!! Or an old quarry
