A good offense army consists of a mix of infantry and cavalry units. A good mix is a ratio of 3:1, that is three infantry for every one cavalry. Romans should have a higher infantry ratio.
Infantry are more powerful attackers than cavalry. By having a 3:1 infantry to cavalry ratio, you pack more attack points for the same amount of crop.
Every offense army should have at least 300 rams, and ideally 350 rams.
When building an offense army, an important rule to understand is the whole is greater than the sum of its parts. A single army of 2000 axeman is stronger than two separate armies of 1000 axeman.
As shown in the simulation above, two separate attacks of 1000 axeman didn’t manage to defeat 1800 praetorians. But a single attack of 2000 axeman managed to defeat the same number of praetorians.
Therefore, offense armies should be built from the same village, and the best village to support a large offensive army is your capital. Being a 15 cropper, you need to constantly push resources to your capital so you may train troops there.
If you understand about village specialization, then you will understand that your capital is an offense village. It needs a maxed out barracks, stables, workshop and blacksmith.
Fully upgrade your offense troops as fast as possible, including catas and rams, then demolish the blacksmith to make room for granary. Do not train any defenders in your offense village.
It is common to run into negative crop. When you have setup your second offense village, it too will run into constant negative crop. Normal negative crop numbers run in the range of negative 20,000 to negative 50,000 an hour.
Don’t worry about the huge crop drain. As long as you continue to push crop to it, you will be able to feed this army.
One of the nice things about a 15 cropper capital is the high crop yield, especially those with high crop oases bonus. This is all the more reason to choose the location of your capital wisely.
A capital should only receive resources. It should not send any resources away because these resources are used to extend croplands, and to continuously train offense troops.
You need to constantly train troops in your capital. If you don’t you will fall behind.
In order to support such a high crop drain, build at least four granaries and as many as six in your offense village. A large warehouse helps too if you want to NPC resources into crop.
Your offense villages will need to be supported by troop support village. 15 croppers and 9 croppers are better than 6 croppers because of their high crop production. Use these support villages to push crop and resources.
When you are not using your army, park your troops in support villages to ease the crop drain. Troops parked in oases are safer because oases are seldom attacked.