Why is the Glorious Heritage a cruiser rather than a battlecruiser?

Why classify the Glorious Heritage as a heavy cruiser rather than a battlecruiser?

Its independent deployment, fleet numbers, duty profile, and stated classification all fit a heavy cruiser, even though the Commonwealth uses it as a capital asset.

Classification rests on employment as well as weapons. Heavy cruisers are numerous enough to investigate and cruise independently, whereas battleships and carriers are treated as concentrated capital assets. The Commonwealth calls the Glorious Heritage a cruiser and sends it on the independent missions expected of one. Its lack of the heavier weapons fit proposed for a battlecruiser supports that classification, even though the fleet uses it as its principal capital ship.