[Marcello]

"there isn't any real way to get artillery units to do this bombardment/quick shoot and then be inactive for a certain amount of time while the gun was allowed to cool down and return to a safe level of operation."

But IIRC (I do not play that much, I have more fun hacking OOBs) guns are not available all the time anyway.If they are cooling down, among the others things,then sustained rate of fire for a few minutes rather than an hour might be a better choice.I do have reservations about including burst fire however, as that down time for cooling down may not be available with sufficient regularity.