Unfortunately there is no world standard in fits and settings to saddles. This is part of the reason saddle fitting is so difficult. No different than our own clothes, go to one clothing store and buy a size 10, purchase the same size in another store, I  am certain both of them will not fit as well as the other. If a saddle rep is to tell you that your horse is a N or  M for example what they mean by that is that is what they would put on the horse, in that brand. Not what the horse needs in every brand.