I am so disappointed this article didn't even touch on AoE2 - it has a pretty amazingly well tuned approach to this problem with extremely finely targeted (except back when camels were technically boats cough) bonus damage system. To compare it to SC2 is hilarious - SC2 has more hard counter systems than most games (both visibility and flight are common uncounterable attributes) and yet for all that countering tends just to be a question of how much and how wide the splash damage is when attacking tightly packed formations. High level SC2 eschews huge portions of the roster since they're essentially irrelevant - AOE2 definitely has strong preferences but most of those units get to see action pretty regularly... except the siege tower.