Upgrade or alternative upgrade?

The combat unit deals less damage, but it has a larger area of effect and its landing spot is predictable (by the way, this isn't a problem when attacking castles)... However, with the royal unit, you can create a powerful force with the support of other troops, if they survive... It has a small hit-and-run capability...))) And it has more hit points... I don't know how to choose, but logically, the combat unit seems better to me...
P.S. A random observation: if a catapult is hit by a pike unit, it doesn't attack. I don't know about other machines...