Not in MMORTS mode - as each of your 4 towns is a new campaign instance. For example think World of Warcraft - one of your town is Elven Mage, and another is Dwarven Warrior.
However - some resources - like Influence, can be traded between your towns. This could be a good boost if you already have a well established town and your starting a new town.
And in Kingdom Wars campaign - all of your town can trade between each other.