The more troops, the better.
The higher tier, the better.
Always keep lower tier troops around for menial tasks like gathering resources or a gnat attack.
Keep in mind, siege engines are ONLY for offense. If you want a defensive force, you can skimp on them initially, but you'll eventually want them for rallies and attacks.
It really is a game of rock/paper/scissors (assuming relatively equal strength).
- Cavalry beat Infantry
- Archers beat Cavalry
- Infantry beat Archers
- Siege beats walls
- Everything (except walls) beat Siege
- Walls beat everything (except siege)
- An easy way to remember this is with the letters IRCI.
( Infantry vs Ranged,Ranged vs Cavalry,Cavalry vs Infantry.)