(Hero - Rogue) in Heroes 4

That's exactly the point – you always have to consider the map's features and the game's mechanics. These chains are not suitable for online play...

I disagree. If the opponent manages to create a chain leading to your castle and goes first, they can, on the first day of the week (referring to Heroes IV), before you've bought your troops but they have, move their units into that chain and attack your fortress. I played online once, but I've played hot-seat mode many times, which is almost the same as online. That's why I know what I'm talking about.