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.

RoR'ing 1:1 retals, despite the fact that it happened to you once by a now inactive member several sets ago, is actually super uncommon, and was done that one time to mess with you on purpose. The leaders of that clan, however, if contacted before they were hit with war attacks, would have made right their members RoR. And that's where you failed at diplomacy.