So I've had the same saddle for about 3 months now and I have never really had any problems with it. I got a new saddle pad, but this is a much better saddle pad then I've had before because the one I got is a Tod Slone 1inch wool pad. So I rode him in it on Wednesday, and when I took the saddle pad off, he was only sweaty behind his shoulders on both sides. I'm assuming this is where all the pressure is. So I rode him again yesterday and I only rode for 15 minutes because he was acting extremely irritated. He was speeding up, wouldn't stay at a walk and He was getting ready to rear up on me and he NEVER does that, or really never even acted like that before. So I got off and took him out and the round pen and see if he was lame or something. And he didn't seem to be bad except going left he would NOT go left at a canter. I got him to go left a few strides but on the wrong lead, and then he would just turn around. So I ran my hands of his shoulders with about 1-2lbs of force and he flinched every time right where he was sweating before and on his shoulders.
I stretched his front legs and back legs and that didn't seem to bother him.
So I don't know if it's my saddle or what, and there is no way that the saddle is too narrow on him.