Padding and Saddle Fit
Padding is part of the western saddling system. You should never ride a western saddle without padding underneath it. But padding does affect how the saddle sits on the horse compared to a bare saddle. So even though we say to check the saddle bare to get the best feel of how the shape of the bars match the horse, you need to understand what padding will, or will not do, to that comparison and to fit of the saddle as a whole.
https://www.rodnikkel.com/content/saddle-tree-blog-from-shop-and-desk/effect-padding-clearance/
https://www.rodnikkel.com/content/saddle-tree-blog-from-shop-and-desk/effect-padding-front-back/
https://www.rodnikkel.com/content/saddle-tree-blog-from-shop-and-desk/effect-padding-rock/