We have Soay. Haven't lambed for the last couple of years but didn't have any problems when we did.
Foxes pretty well controlled by gamekeepers but we have lots of woodland around us so foxes do come and go.
Local shepherd advised us to pen any twins or weak lambs overnight so they had chance to get a bit of strength. He said that the fox would often target a ewe with twins so that he could take one while she was distracted with the other.
Ours were great mums though and really alert to dangers and quick to face off anything that came in the paddock. No dogs,cats etc allowed anywhere in their patch!
At night they tended to rest in a circle at the top of the hill with the lambs in the centre and adults around them.
Also very noisy if they thought anything untoward was going on ..... Like ravens hanging around in the day.