Most any stock will have some drop to it, at the comb, heel and toe. Some much more than others. The early Fajan straight thumb hole comes to mind vs the huge drops on the early Shutzen rifles. There are all sorts of combs as well. Think the M1A with its more or less straight stock in terms of the comb and the very popular European stocks with the molded, inset cheek pieces.
Now add in the differences in facial structure, neck length and thickness and the general flexibility of the shooters and it is a wonder any stock works.
The good news is that with the exception of left hand/right hand, most stocks can be made to work, more or less, and adjustable stocks make the task easier for all provided you have some idea what you are doing.
The secret is to get everything positioned so that when you mount your rifle, in you normal shooting position, everything lines up with no stress or strain anywhere in the position. The less stress, the more accurate your shooting will become. Positional shooting will compromise this somewhat as differences in butt stock to shoulder position can vary a little as can the angle of the neck between prone and standing. Some compromise should be acceptable. In the ideal, with your rifle mounted, you want minimum strain in the neck and shoulder area. You should be able to hold this position for a long time and not get tired. Your eye needs to be aligned directly behind the scope and centered vertically and horizontally within the eye box of the scope without having to force your cheek down into the stock or stretch your head out like an Emu to get there. The average person should have no problems with this. If you are outside average dimensions you may have to work a little harder. The same stock is not going to work for a guy with a 13x29 shirt size as a guy with 22x30 or 18x36 shirt.