Well, we must have different situations. I can't imagine not having some kind of scheduling program for 10-15 hunters, some of whom live over an hour drive from the property, myself included.
To not have a system in place to make sure everyone knows who is on the property, including when and where they plan to be, seems impracticable, dangerous and legally untenable for the owner.
Drive 90 minutes to find out someone is in my spot? No thanks.