Why an exploration cruiser needs exceptional volume

The comparison is to age-of-sail exploration vessels that surrendered potential armament and crew space to laboratories, stores, boats, and specialist functions. A Galaxy must still retain cruiser-level mobility and fighting power, so exploration capability adds volume rather than replacing military capability outright. Its shuttlecraft provide the equivalent of an explorer's boats for detached investigation. Starfleet science officers need broad competence, while deep exploration also requires civilian specialists whose narrow expertise would not sensibly define a normal naval career. The resulting hull is large because it combines these communities and facilities rather than because every cubic metre serves combat.