Castle shadows are cast below neighboring castles

[zenseii]

Preliminary checks

• [X] I've checked that there aren't other open issues on the same topic.

Describe the problem requiring a solution

The top of the Necromancer castle tower goes below the bottom of the knight castle. Marking this as improvement since it is like this in OG too and this isn't something you'll see in many maps (at least not in normal ones that aren't just made for testing purposes).

Describe the possible solution

The Castle shadow should be cast on top of the neighboring castle.

Additional info

No response

[ihhub]

It is related to #5716 .