To sum up
In summary, we can say that a taller person would need a gun with longer stock and a higher comb, a medium height person will need an average length stock with a slightly lower or more normal comb and a shorter person would need a shorter stock with a lower comb.
With the help and advice of a good instructor and gunsmith, alterations and adjustments can usually be made to your existing gun to help you achieve a good fit and improve your shooting success.
There are all sorts of items available to address these issues, such as simple slip-on butt extensions in leather or rubber, and temporary comb raisers, as well as professionally fitted adjustable combs. In the event of your stock being too long or altering the cast, then a gunsmith is your best bet to professionally deal with those issues.
On the other hand you could always treat yourself to a brand new gun that is just right for you!