Would a carrier's guns add much at Cape Matapan?

Would the carrier's guns have been useful if she had stayed in the line of fire at Cape Matapan?

They could fire effectively, but their contribution would be small beside close-range 15-inch fire from three battleships.

The answer considers the additional effect of the carrier's 4.5-inch guns. Three battleships are already described as firing eight 15-inch guns apiece, twice a minute, at close range. Under those conditions, the smaller guns would add little to the destruction of the Italian cruisers. The comparison concerns marginal contribution during that engagement, rather than the general usefulness of the carrier's armament.