My horse gets thick winter hair as well (I blame it on the mustang in her). It's not abnormal, in look or length, just a little thicker than most horses out here. It's cute the first month, then it is just plain annoying
Kigerqueen, I feel your pain. Our riding season is plagued by hair trouble. Because I do jumping, liberty work, basic dressage, and other strenuous work with my horse, I will be giving her a full body clip this winter, leaving head and legs alone. However, I will be hiring a groomer to come out and do the initial clip after she fully grows that winter coat. I'm not experienced or confident enough to do it myself.
If I were you, I would try a trace, irish, or other kind of partial clip. That should help your horse, and seeing as how you are already a dog groomer I think you could do it
Forgot to add, as you said you will still have to blanket which is a hassle when your horses aren't at home like mine are. But I think there are clips where you can leave them without blankets, as you only clip a small area. Hey more experienced clippers care to chime in on this verdict?