Combining twin Phalanx mounts with RAM

Would a combined twin-Phalanx and RAM mount be useful, and which ships would carry it?

It could be useful on carriers, with missiles engaging first and guns firing at close range, but the weight and complexity are substantial.

A combined installation could use Rolling Airframe Missiles for the first engagement and twin Phalanx mounts when a target closed within gun range. Carriers are suggested as the ships most likely to use it. The concept is considered potentially useful, but complicated and heavy for what it provides. One objection is that accepting that much weight would make a gun larger than 20 mm preferable.