Rocket artillery truly is worse than regular artillery. Sometimes there isn’t a point in using it
First, add Rocket artillery to base Radio Operators. It should be an upgrade like bombing runs, smoke, supply drops, etc. Its an entire waste of a feature if a few premium squads just have this ability
Second, overhaul Rocket artillery to make it a more interesting feature. This will give it pros and cons as to whether to use it over regular artillery so there is more choice and makes battles more dynamic. There were significant differences between gun artillery and rocket artillery
Give Rocket Artillery a shorter cooldown than regular artillery. Rocket artillery was much cheaper to produce than regular gun artillery. They were less complex than intricate rifled gun artillery. They were also lighter and more mobile than gun artillery pieces
Give Rocket Artillery a larger radius and make their rocket strikes random. Despite being more cheaper, simple, and mobile than gun artillery, they were far less accurate.
Give Rocket Artillery a faster firing. Despite being less accurate than gun artillery, the primary use of rocket artillery was to quickly saturate an area. It was essentially more of a psychological weapon with mass fire in short amount of time
So with Rocket Artillery, you would be able to call in mass fire support quickly with the potential to hit targets in a larger area that the enemy can’t easily avoid, but they are random and inaccurate; while gun artillery can devastate a smaller area more accurately but has a longer cooldown and the enemy can more easily avoid.