Rocket Artillery morale damage

Rocket artillery currently does too much morale damage to provinces. 10 level 1 rocket artillery can take an enemy province from nearly 100% to 0% morale in 2-3 hours, even with buildings/forts/garrison, which is too strong. Comparatively regular level 1 artillery would take at least 8 hours to do the same.

I like that artillery has a more strategic aspect in the building and morale damage but it needs to be tuned for certain units. I don't mind the similar damage rrguns do since they are a more significant investment and come much later in the game.