Don't remove capping ability just make it like it is in DoW II: make it so a unit cannot set up if it wants to capture.
Poll edited to be more open-ended.
So if a Maxim is sitting idle, capturing and an enemy unit approaches, it stops capping, sets up and starts firing?
It would be the same situation with a tiny delay for the Maxim spammer. The maxim would push off the enemy unit, then cap in the 60 seconds it takes said unit to retreat and come back.