Pikemen (significant increase compared to ballistae, better stats)
Monks (increase and ranged attack)
Champions. Let's discuss this in more detail. An angel revives them, but this takes 1 valuable turn, and the ability is one-time use. 4 per week – this increase can be achieved without heavily developing nobility (e.g., buying them at the Academy or elsewhere) and without wasting precious experience. Level 3 nobility, and you already have 5 champions per week! If you don't spend them excessively, and considering their first attack, they can simply overwhelm the opponent with numbers. And on a small map, a champion is preferable.