Just be careful if you use one to reset it regularly, or it can dig into the withers and cause a nasty gash. Had that happen to a pony of mine once when I went on vacation.
Yes if you plan on clipping him, if not, he'd be fine without
My horse has a very thick coat and does not move around much in his paddock and still manages to get shoulder rubs, at least before I bought the shoulder guard. It might just be something to have around just in case.
I don't think it's going to do anything not having shoulder guards I've never had problems or seen problems with blankets!
He should be just fine then :)
He's a Welsh cross, so he gets a heavy coat. Currently stays in a paddock, so no running around.
If skin sensitivity isn't an issue, I wouldn't really worry about it. How thick does your horses winter coat get?
We blanket our horses every winter, and none of them get rubs... does your horse have sensitive skin? How much time do they spend running around in turn out?