I didn't say they used a (years old) AoE engine, just "engine", 'cos it's the "Essence Engine" made for Company of Heroes (by Relic) for their 2006 release.. And what I hear about it is that it's not great, even though they continue to work with it (considering they release "new" games with it).Every aoe has had this since AoE3 (not sure about AoM),
One can argue for not missing with arrows in aoe3 (game balance and stuff with mainly gunpowder units), but that's not a medieval game.