I actually like this idea, more Alliance Oriented, and a sort of "Alliance Event"
Problems could arise due to Larger Alliances winning all of the time, but the "land" to fight over would be global and could give resource production
There's another thing too, how the servers would handle it. Alex doesn't take heavy updates due to server issues, and this update involving a new land system constantly changing with Alliances that have hundreds of people participating could heavily strain the servers