The papers of 1913 are full of stories about the Helmsdon Monster. It is possible that some similarity between the killings can be reached.
1 The Monster is a ghast summoned by some foolish farmers dabbling in the occult. It came up through the caverns that riddle the area and began slaughtering the sheep. By day it hid in the caverns, by night it stalked the moors.
The farmers were terrified by the thing they had unwittingly called, but were powerless against it. However, the stories in the press attracted a sorcerer who came and bound the ghast to the caverns.
The sorcerer has just recently died, releasing the ghast from its bindings. Once again it is reaching out to the surface and feeding on the sheep it finds. Eventually it will get brave enough to attack individual homesteads.
2 The slaughters are the work of one crazed lunatic who roams the moors, killing the sheep with his bare hands. He is completely insane, and very dangerous.
3 The creature is a large wild dog, a doberman. It is quite canny and will do its best to avoid capture. It was a guard dog at a nearby manor, but was set free during a drunken party. It will attack unhesitatingly.