I'm slighty fed up with the pure Wilts lambing at 135% - it is fine when breeding purebreds was my hobby, but now I'm expanding to have sheep farming as my business, I cant afford that level of production.
We're commercial beef and sheep farmers and we are delighted with any ewe who produces and rears a good single lamb.
We can get most of the singles away without any intervention at all. They grow well enough to be sold off their mums - no weaning, no castrating, no meds, no cake, no need to take especial care of mum, mum is unlikely to get twin lamb disease, mastitis, etc, recovers condition quickly - and ewes who have singles will last more years. The lambs getting away sooner usually means best ppk (pence per kilo) too.
We had a batch of Lleyns and liked them very much - except they had too many twins and triplets!