General rules for online games.

How much time does it take to walk back and forth a couple of times on a large map? For fans of the "hit and run" tactic, there's Chains of War. There are also heroes who are more "cheesy" in this regard, not requiring extensive development and ranged units (mages, skirmishers, etc.).

IMHO
Wing should be strong at high levels, as his development speed is not very fast (unless it's Osia in a tower with her archers, or Gil with dancers, Ilfina would also work).