Would like to ask the developers to increase the attack of the Town centre, Towers, castles etc (x3) and double the amount of attacks when garrisoned.
The problem is that infantry units as well as cav find it too easy to attack and destroy defensive structures. It actually makes all Seige weapons redundant. Increase the hack armour of defencive buildings.
Oh, oops, I now see you are talking about AoM. Sorry, I was replying as if it was AoE2. Sounds like the two games may share some similar traits regarding this