Your ideal stack and how you use it

[Vladimir]

Well I could just get an army of 20 Turkish Horse Archers / Turkomans...

Or Italian Spear Militia and Pavise Xbows as the Italian factions...

Or Mailed Knights with some others as anyone else...

Any of those armies can pwn the world. But they're not quite the 'ideal' stacks.

Spam is far from ideal. Every time you overspecialize like with your horse archers you set yourself up for defeat. The army also shouldn't be faction specific. The army I use is ideal because it requires little infrastructure to raise and support, is maneuverable, flexible, and can be easily upgraded to incorporate new technology. Even as powerful as the Italian militias are, their relatively limited number of cities would be hard pressed to field enough men.