This sounds like a great idea. I would like to hear your thoughts after trying it out.
So, it was marginal success.
First I didn't have nearly enough islands on the map. I need to totally remake (and recopy) all of my maps. The kids struggled to narrow down my path.
In the second class we played and instead of moving one unit at a time, I moved several in one direction and then turned. This gave me a longer path for them to try to line up. A few kids figured out to do the overlay and I think next time I take it out I'll give them overlays or tracing paper to use as part of the activity.
The time after that... we introduce silent drives.