Just a quick question about unit size. When I begin my first campaign, unit sizes are as such:

Cavalry & Knights: 40
Infantry: 60
Spearmen: 100
Archers:60

After beating the campaign, unit sizes increase by 1/3, roughly. I'm assuming that after you beat a single player campaign, depending upon what difficulty you defeated it on, the unit size is upped? Am I wrong on this, or...?