The better a saddle fits a horse, the less you have to worry about needing horse blankets. Saddle blankets were originally used just to keep the sweat off the saddle. To do that job a thin wool Navajo Indian blanket worked just fine. Nowadays there are hundreds of saddle blankets available ranging from high-tech to no-tech. Saddle blanket manufacturers are taking advantage of the fact that between 60% to 70% of the horses in the United States are estimated to being ridden with saddles that don't fit properly.
We run into people all the time who spend over $1000 on a saddle and then have to go out and spend another $200 to $300 on a pad and blanket to help 'fix' a saddle that doesn't fit correctly. Saddle blankets can take up some of the slack if your saddle isn't a perfect fit but there is definitely a point where if a saddle fits so poorly that no saddle pad and blanket combination can make up for it. Prevent a bad saddle from causing the horse (and likely the rider as well) pain and irritation - make sure that the saddle you choose fits the horse and rider it's intended for!
Saddle Blankets