I'll be honest. I think you're choosing not to hear me and intentionally be obtuse. I'll try once more but then I'm giving up.

Warclans will often enforce a 1:kill policy against people who hit them without contact. This is because their desire is war, and you've provided a target. Don't poke the T-Rex with a stick, however, and you won't get eaten. Outgoing grabs from a wartag, however, will generally be resolved with standard retals. It's good to contact them anyways and let them know what's up, but generally 1:1 will be accepted provided the person makes contact.

For literally everyone else on the server, occasional land grabs happen whether because of people not following leadership policies, or a clan that isn't all x and allows their members to do LGs on non-friendly tags, small tags or untagged. In most cases, if you contact those clans regarding simple LGs, they will either tell you to take retals for your land, or provide a target within their tag that you can take retals from.