I have a question regarding this point. You can escape, and you can buy back an escaped hero. But if there is only one castle, and let's say 2-3 heroes need to escape to it at the same time, how can they be bought back if you can't move them on that day?
Or do you mean that you can't have more than one hero escape? Maybe allow the rescued hero to move along the castle so that he doesn't block the gate, or something?
If you have 1 castle, you can have 10 heroes escape, but you can only buy back 1 of them on that day in your only castle!
If you have 2 castles, then 2 heroes, and so on.