Can Factions Move to another foothold?

[DownloadFailed]

I've thought about this and wondered: Can factions move to another foothold? Currently, I picture the three factions taking up their respective thirds of a continent and more or less staying there, stagnant. If footholds don't move between factions, then each faction will pretty much always have a set of territories that will almost always be theirs and factions won't stray too far from their "side" of the continent. Only the middle of the continent would be hotly contested over. Territory shifting is fine, but entire empire shifting would be cooler.