What it all boils down to is the kind of war you expect to fight. Over a prolonged shore engagement the Zumwalt guns will be far cheaper than Tomahawks, for a

What it all boils down to is the kind of war you expect to fight. Over a prolonged shore engagement the Zumwalt guns will be far cheaper than Tomahawks, for a lot of reasons. But they're a pretty specialized tool - at shorter ranges the old 5"/62s would have done the job, and missiles will still be required for longer ranges.