Ponker
Loving the herd life
Most sheep breeders don't test or don't care-
This isn't true. Many sheep breeders test for OPP, Johnes, and Scrapie resistant gene at codon 171 and more people are starting to test even further for Scrapie resistance. I belong to the Finnsheep Breeders Association. In the Finnsheep community testing is primary. Sheep don't leave home to enter another flock without blood tests, and flock tests negative for OPP since that test isn't accurate in young lambs.
As for the size and of the shelter, I'm with @chiques chicks I use portable electric netting and regularly move the herds around. At night the sheep come to the barnyard which is a permanent fenced area closer to the house. It is a smaller area meant for lambing and working the herd. I feed them in this enclosure depending on body condition and check each one. It isn't hard, I'm stroking each ewe and giving scratches. I use this time to make sure everyone is healthy and has correct body condition. In this small area, it is easier to give medicine, drench, shots, trim hooves ... So while this enclosure is smaller, they are out on grass all day. It is more work and they mess the place every night which means cleaning it every morning. But I have peace of mind they're all in good shape.
The goats have an 80'x100' area where their shelter is permanently fixed. It is an 18'x20' converted carport. The buck and his wether are handled separately.