A modern role for the arsenal ship

Could an arsenal ship be a useful future warship concept?

Possibly, especially as a converted merchant hull carrying extra missiles for a battle group rather than as a wholly new capital ship.

The arsenal-ship idea dates to the beginning of the missile age, when an all-missile ship seemed the successor to the all-big-gun ship. The quantity and cost of missiles needed to justify a dedicated design have repeatedly undermined the concept. A more plausible route may be a rapid conversion of a smaller container ship rather than another purpose-built capital ship. Such a vessel could add strike or surface-to-air missile depth to a battle group while relying on other ships for much of the wider combat system.