Herding Instinct in Dairy Cows

I manage a herd of 3000 cows and 3000 followers in the Middle East. One historical issue that I am trying to address is the behavior of milking cows in groups at the extremities of the herd. The problem is most pronounced in Summer day time. Milking cows crowd together in the loose sand and manure bedded sheds at the closest point to the nearest group and in some cases only use only up to 40% of the expensive cooled shaded space allocated to them. This means they generate and lie in congested muckier areas and thereby increase coli counts, increase scc's and clinical mastltis, unnecessarily. This issue has phased present and previous management and many consultants that have visited the farm. This issue affects the 8 sheds at the extremities of the herd by different degrees These sheds are all of different orientation so the aspect of sun, flies are not common factors. The one common factor is that all the sheds are at the extremities of the herd - so my theory is that it is the herding instinct of the cows that makes them want to bunch as close as possible to the core of the overall herd. The cows spread out well at night time so it might be that they cannot see open spaces outside them in the darkness.

Two solutions I am looking at are: 

1- Blind off the end of the sheds and sand yards with sheeting and the feed passage with black plastic strips.
2- Make small enclosures at the unused ends of the houses and place 5 or 6 cows in each after milking to get the rest of the affected groups to spread out towards them.

I am sure other herds have experienced similar issues of this nature, so I am interested to hear ideas and opinions from any quarter.