Regarding building defense, yes, I agree; I was just too lazy to configure each one individually. This will be added in the new version, and, of course, even creature squads will consist of several groups of monsters.
As for buying artifacts, the price can be increased. The problem is simply that the AI steals them, especially the Dragon set...
The Elf castle is more complicated; in the Light Path, you give it back to them. If you destroy it to zero while it's under the player's control, the elves will have no chance against Blue or the Mage. Perhaps a script for rebuilding it could be implemented.
Thank you all for your feedback. I'll wait a little longer and then start working on the improved version.