3rd annual offline tournament "Best of the best"

In my opinion, the first day is about 1/3 of the whole game. I haven't finished it yet, but there's not much left. And here's my question. Is it just me, or does the hero recruitment mechanic work poorly (only in the outermost castles, it works normally)? And in what cases can't you recruit a hero (besides the obvious ones)? I've noticed that if an enemy hero has fled, you can't recruit him until you destroy his castle; apparently, he's hiding in the tavern. And now I can't recruit another computer-controlled hero, even though everything seems to be okay.