Gotcha.
I don't claim to be an expert on shotgun fit. I did however spend 25 years training male and female shooters, of all shapes and sizes, how to manage patrol rifles & riot guns with hard-kicking loads.
The 'crook of the arm check' or whatever you wish to call it, is not the end-all be all of stock fit. It is however a relevant indicator of whether an individual shooter is going to have difficulty managing a particular long gun. Miss that dimension by an inch or more and it requires exponentially more effort on the shooter's part. I saw it too many times to be convinced otherwise.
