What difficulty is coming up with adding the NA server to the options? I don't think Scheduling is the issue since I've seen multiple battles scheduled at the same time likely due to selections made back from when NA was an option for server choice. Are you having a problem making the database listen to more than one server at a time?
Either way, I agree that something should be done since the battles are piling up a bit too fast. Until the other server options become available, can you disallow attacking when either army has less than 50 troops? This would avoid some of the more stupid battles so more important battles aren't scheduled for 2 days away. Hell, it's going to start being a week away once they really start piling up.