I'm sorry, but I really don't think that is a reliable counter. Machinery comes significantly later than iron working, chances are you will die in multiplayer before you come even close to getting machinery. Also, in early game (multiplayer) there really isn't that much production to devote to spamming ax men.
Axeman 35
Praetorian 45
In combat they are as good as matched.
And you can whip axemen in defence, whereas attacking Praetorians have to march all the way to your empire.
You may not think it's a "reliable" counter, but it's a good bet.