Red crystal

I'm playing the "easy" version with a human hero (I failed near the end of the second month on the hard difficulty). So, something's not right. After repelling several sieges, around the middle of the second month, a hunter appears and offers to block the portals for a month in exchange for ownership of a castle for a week. If you refuse, an enemy with a huge army appears two days away from your castle, and it's impossible to resist. As a result, you agree, but the castle isn't returned after a week, or even after two. For two weeks, I've been completing tasks (portal, clearing the path, caravan) and even captured a castle with a shipyard. But here's the problem: another enemy with an enormous army appeared, even though it's only been two weeks since I met the hunter. Is this some kind of trick – the supposedly returned castle after a week, the month of peace – or is it a bug? And also, is there too much "meat" (units) in the enemy armies?