Creating fantasy armies or "custom" units

[Phrip]

Is there any ability (or future ability) to create "fantasy" armies, or to select units from different historical armies to create a "custom" army? As it seems now, I can only create an army based on a single historical armies units. It would be great to have access to all units or the ability to create custom units. I would love to be able to create fantasy based armies, such as the ones being discussed on the Lord of the Green Dragon's website.
http://lordofthegreendragons.blogspot.c ... omads.html