We have only had one instance of 'hassle' from any Soay tup. He was a ram lamb in his first season and when the first lamb was born nuzzled it, as if he didn't know what it was. I took it and gave it back to it's mother and he then came between me and them to defend them! Thereafter he was a real defender, and no problem at all.
We have kept ours together, along with whethers, or sometimes separated them if the grazing wasn't enough for the whole flock. The tups really defend the whole flock, whereas the ewes look after their own a bit more. I have seen the ewes circle to ward off a fox, and the ram advance towards it stamping his feet.
As flock animals they need company, so I would keep a wether or two for that purpose.
Best of luck,
Teirw