Arrows in Heroes 2.

However, yes! 1 iron golem might be enough to defeat a troll in this scenario. But it won't work with 1 halfling – the troll will defeat him in the first turn.

So what? As far as I remember, the army's morale, whether positive or negative, is determined at the beginning of the battle and doesn't change. Otherwise, it would be very convenient – you could sacrifice an extra unit, improve your morale, and fight calmly.