Guard Towers would be a fantastic addition to this game. It would be wonderful for all players regardless of their politics. It's a win for both sides really..
They could help provide defense while the hero and army are away, for both sides.
Another option could be to treat them like the Enchanted Tower & Sage... but have the Guard Tower attack siege :)
We all loved the Guard Towers in TTG lol... we are the player base at this time but it would be good addition for all, now and in the future, I believe.
And maybe implement it in classical or earlier LOL