Ok, this is not much to work with here, but for one thing ... when you submit a scenario you should give at least a good 15 minutes worth of it instead of just picking your guy and that's it.
Second, display instructions about picking a guy with your king.
Third, put the selection of the heroes in a contained place, for example, surround it with water and bamboo on the shore.
Other then that, there's not much I can say, nice idea though. Hope all turns out well! (Main reason for score so low is because it's not a complete demo!)
"All is well with Elves by your side!" ~ Sir Danial