Outlaw 4!

You were spot on. We tried to start a game with the Castle on map 112, but we hesitated and put the save aside for now, but now everything is clear.

We also encountered a bug with "nowhere to go." The starting town is located in a forest, and there's no way to leave, not even a single free space. We decided that in such cases, a clear restart is the best option, without any subjective losses, as opposed to having 3 Castles.

Added 24 minutes ago

Regarding the final battle, it makes sense, but it's not very clear. Does that mean both players have to reach the desert on day 347?
1) And who attacks first?
2) What if one player doesn't make it to the desert on day 347? For example, they get stuck in a blocked area, and they don't have enough damage dealers. Is that an automatic loss?
3) What if there's no desert on the map? Any terrain gives the player bonuses, which can be decisive. Or there are 4 deserts. One desert might be more convenient for one player, and another for the other.
4) Let's say the red player played as a Logistician, spent 4 months running around, stealing towns and troops, and staying in Castles where he couldn't be defeated, while the blue player spent that time leveling up 3 heroes, and since all the troops of all factions can't be put into one hero, he placed all 3 heroes on the desert. Does that mean the red player chooses who to fight in the final battle? Or does the red player have 3 heroes, and the blue player has 3 heroes, and all the troops are divided among them? If attacking in the Castles wasn't advantageous for either player, how would the final battle be conducted?

In offline tournaments, I don't know how it is now, but before, the battle was fought between 2 optimal heroes, chosen by the players, based on their stats on a specific day. The heroes were "taken" from the saves and placed in the arena.