You're making the perfect be the enemy of the good.

Making sure buildings are near the street listed, in the right range of numbers, is a system that works in most regions and should be encoded and used for checking data.

I wouldn't automatically assume that they don't have such checks. Checking an entry for reasonableness is a good idea, but it needs to be overrideable. Sometimes you'll need an entry that isn't actually reasonable by whatever definitions you use. And then you'll tend to have your workers get used to the override and not actually think about whether it might have a point.

So who's responsible for then figuring out what nested regions, and nested regions of nested regions, and nested regions of nested regions of nested regions, that then does and doesn't apply to?