Why a huge auxiliary fleet implies a much larger navy

How would the Royal Fleet Auxiliary react to receiving twenty-four Wave-class, eight Tide-class, and six Fort Victoria-class ships?

It would welcome them, then ask what much larger Royal Navy it was expected to support.

The proposed auxiliary inventory implies an unstated expansion of the combat fleet. Replenishment ships, stores vessels, and tankers derive their value from the formations and distant operations assigned to them. Buying support hulls without the warships, crews, and deployment plan they sustain would invert the normal force-structure calculation. Fleet logistics must therefore be sized as part of the whole navy.