If you shoulder and shoot iron sighted rifles properly, they all pretty much shoulder the same way
Pretty much true, but, and there always is a but in life, I am a maverick at this kind of thing. Some rifles I cant, some my elbow is up, and some is as you describe. I make the rifle fit me, and not me fit the rifle in most cases, and have won 12 medals in the World Police & Fire Games. I did the same thing in martial arts, and did equally as well back in the day. My style was no style, and I changed depending on who I was up against.
Stocks: My old Weatherby 300, a german one I think it was, had a stock that made it difficult to see the animal when hit, as the muzzle climbed like the current tax rates! My CZ 416 Rigby with the Euro-stock shot much different than my Current CZ 458 Lott with the Americanized stock. My Springfield Supermatch stock shot great, but the neck was so fat I had to adjust my grip a tad. My sweetest stock of all is my custom Flintlock which fits me like a hug from Cindy Crawford ... I love it!
The AK stock feels like a board ... but I still shoot it well...
I am not sure I like pistol grips on my stock either...