LOP is an area like pitch and how chokes work that is a magnet for bad opinions and mis-information. Some time ago I stuck one of those extendo kinda things on a trap gun to decide absolutely what the best LOP was for me. I went from about 13.5" where I was in danger of bashing my nose with my thumb, to just under 16 where it was becoming really strange trying to mount the gun. The Difference?? Nothing. Of course no other aspect of the gun fit changed, which was just fine, just the LOP.
Now, pragmatically, the best fit is long enough that you don't bash your nose. Why? Obviously that will accomdate the easiest gun mount and the greatest range of clothing. And more importantly it will bring the center of mass close to the rotational axis of your body and you will be able to turn faster. (don't bother, Rocketman, you know I think your MOI is crap for years now ;)). But short stocks look kinda funny tho, don't they? So cut it or leave it alone or whatever. It really doesn't make any difference in anything but how the gun mount feels. Of course that presumes that the gun fit is otherwise correct and that begs a lot since most shooters have NO clue how that works either.
The really important point here is to find something to obsess about that matters.
JMO of course, but that's just the way it is
WtS