That’s honestly the worst rule I’ve ever seen. Just keep letting all the mature crap racks or 4, 5 and 6s keep bullying all your great up and comers to the neighbors property.
Would be interesting for MBrock or someone to chime in but I've always heard that a "cull buck" doesn't really exist and 95/100 deer in AL will grow a serious rack if allowed to mature to 4.5 years once their skeleton develops. Obviously if you have some deer that the club has identified as 4 years old and it has antler deformities or something you'd make an exception and cull it.
If you have 12 guys hunting say 1700 acres, there are maybe 4 let's say stretch 5 fully developed mature deer on that property, depending on the habitat. So if each guy harvests a mature buck every 3ish years I don't see why its a bad policy to require it be mounted. That's assuming your target is managing for trophy bucks and not just having everyone shoot 2.5 year olds.