I had two Honey & Bramble, North of England Mules (Leiscester x Swaledale) for ten years, I lost both of them just before Christmas. I acquired them as two week old orphan lambs way back in 2002 and bottle fed them. They were easy to handle, friendly and took very little looking after. Plus plenty around Cumbria.
One thing to bear in mind if you are looking at keeping native breeds and especially Herdwicks on lowland grazing, is their diet. They are designed to live on very sparse rough fell, when kept on better grass it can have a bad affect on their feet, with foot rot, abscesses etc. This falls true to many of the hardier type of sheep. The farmers have them up on the fell tops in the summer and only usually have them on the lowland grazing for a few months before lambing.
I know it certainly made a difference with my two keeping them with the horses, they were in the restricted grazing most of the year and even then the grass was too good for them.