Well movement is gong to cause hairs to be trimmed because of friction, exposing the skin to rubbing. It depends on the horse's shoulders, movement and hairs. I would suggest a shoulder protector if his shoulders are rubbed.
I love Weatherbeetas and Horseware but if they're out of your budget, I can recommend Axiom turnout rugs which are sold only on eBay. Sadly they don't offer much variation in terms of weight and are often mad patterns :)
I would recommend the Rambo XL line or the chest extender piece for a broad-shouldered horse. I love my regular rambos for my mare, and she does not get any rubs (and she's quite sensitive and thin skinned.)