More particularly so, as to my understanding, the mechanism of giving out such rewards is already built into the game. You don't need any development or code changes to make it work. It just needs some effort and creativity on the moderator's parts. You guys saw the enormous benefits of the last such event - the civil war battles. It's entirely logical to modify and adjust it in some way to make it happen more frequently. Attendance in battles will only improve, more people will be active and Innogames will make more profit out of the increased activity. What's not to like?
If server overload is an issue, stagger the battles on different worlds on different days. If staff strength is inadequate to organize things on this scope, get some non moderator volunteers from the community to help out.