Length of pull, drop at comb, drop at heel, cast and pitch are all individual requirements. There cannot be a consensus on measurements like LOP, any more than there can be a consensus on shoe size. What good does it do to know everyone's shoe size?
The point of all these measurements is to end up with a gun that shoots where you are looking. On most shotguns the rear sight is your eyeball. Different stock dimensions will place your eye in a different position, which has about the same effect as moving the rear sight on a rifle. A difference of an eighth of an inch in eye placement will mean a difference of 2 to 3 feet in shot placement at 40 yards.We all have faces of different shapes, necks of different lengths, etc. A shotgun with a stock that fits me will very likely not fit you well.
When shooting a gun that has both front and rear sights (or optics) the equation changes and you can alter the position of your eye to match. Stock measurements are less critical. Shotguns so equipped are notoriously bad for hitting flying targets, though.
Obviously we don't all shoot shotguns with custom designed stocks, but we still manage to shoot things with them. Sometimes you just happen to fit the manufacturers idea of the average human. More often though, we adapt to our stocks by scrunching our head one way or the other. The problem with this is that it is hard to do consistently, the same way every time.
Fortunately it is not that difficult to alter a stock to fit you. Add some length, or shorten a stock, build up the comb or take some off, there are plenty of published methods for achieving gun fit. The differences are small, but make a big difference in your shooting.
Sharptail