Thanks for the insightful links. So they did run around in donkey-carts after all. As for your comment regarding the use of pikes against chariots, I believe that's the reason why the roman AI is programmed to leave Macedonia alone when you play Britannia. Pikemen and heavy cavalry are a much bigger problem for celtic armies as depicted in the game than the roman army prior to the reforms (in my game they never got to build an imperial palace in Italy). Pikes really need to be outmaneuvered and struck from the flanks and light chariots aren't really that effective in melee against heavy cavalry, but kiting them just opens the back of your line to a charge, which is what the macedonian cavalry roster is designed to do.

I should mention the funny siege of Larissa. It had huge stone walls, little to no garrison but MASSIVE reinforcements (two nearly full stacks of regular & royal pikes, cavalry of all sorts from light lancers to macedonian cav, some siege equipment and golden archers. I had my guys push the siege towers while the chariots skirmished in front of the reinforcements. Usually the AI will run straight for the gates, but my chariots made it indecisive and while it went between advancing towards them or moving for the gate, I managed to conquer the entire length of the wall, rush all other infantry inside so in the end the reinforcements where locked out with nothing to do but run around the walls after chariots while being shot from all directions.

Needless to say, every chariot unit got an extra one or two silver chevrons from that.