Tactics for playing against Wizards.

IMHO, you need to play aggressively. To succeed, you need to take Wing and sweep away the mage's troops from the first turns, because there's no point in playing defensively, as if it's the Oracle, it will decimate the entire army with magic. Therefore, all that remains is to increase the army's speed and attack, which we do with leadership (or boots of speed) and light magic (punishing mass)...
P.S.: It's dangerous to level up Machines and Chaos!