Just an idea that popped into my head last night for how to 'fix' land claiming. There are a few issues I haven't worked out, like how this would work for really small starter bases, but I think the idea works well for the smaller to large bases.
The idea is similar to how Rust works with Tool Cupboards. You have only 1 placeable that controls building privilege. That building in Conan should be the altars to the Gods. So in your small to medium base, you would generally have 1 altar at the centre that you build your walls around. Larger Compounds would have more altars obviously. If you wanted to control large areas of land, you need to place and defend many altars.
So how to you 'capture' an altar built by an enemy? By wining the favor of the god of course. Every altar can start with a certain amount of favour (or zeal) for the clan that placed it (say 10). If someone just placed a Mita altar, I could then capture it by feeding it 11 Lingering Essence. They could put in 2 more to get it back. If they fed it 100 Essence, I would need to feed it 101 etc. So claiming 'your base' isn't too tough, but claiming large areas needs a lot of work. Even really big clans would have trouble fully controlling a large area. At the same time, a small clan with a focused base doesn't have to worry their building permission will be easy to take away.
I think having a mechanic like this where you have the 'strength' of your land claim is a good one. It solves the blocking out problem, while people don't have to worry about their claims to their bases being taken away so easily. Makes base building a bit more interesting too, as you have to defend a focal point. You can also very easily solve the unraidable base issue by having the altar radium not extend down too far and forcing the raiding activity to happen at ground level.