I would not normally associate using the map edge to cover a flank "gamey" in the strctest sense. The justification for this is that for both sides in a game battle secure the same benefit/penalty knowing that map edges are safe. Granted the value of a secure flank may vary with missions, victory locations, and offensive vs. defensive strategies.
I find the best way to avoid map edge hugging, at least in Quick-Battles, is to use really large maps for relatively few units. The random map generator tends to put victory locations near the center, thus negating some of the usefullness of hugging the edge.