The Uruk-hai were more tolerant of daylight than other orcs. I think it was mentioned a couple of times by the fellowship folks, and there was also a scene when they had captured Merry and Pippin and had to keep running day and night. The commander made fun of the others for being weaker against the daylight.

Also, cavalry can generally defeat a pole arm formation by flanking and using a combined arms operation. They need projectile weapons (arrows/muskets/cannon…) or infantry to keep the pikemen engaged. If the pole arm unit forms a square, it’s largely protected against cavalry but has increased vulnerability to missile weapons and is fairly immobile.

Or just send in the ents.