Hermes could carry roughly twenty aircraft, allowing a hypothetical mix of anti-submarine Swordfish and a smaller fighter element. In that role she would complement Ark Royal by sustaining patrols around Force H instead of trying to duplicate a fleet carrier's strike mission. A force of perhaps twelve Swordfish and eight fighters would put persistent submarine search ahead of strike mass. The two carriers could divide work according to air-group size and mission.
Notable Point · 32:02-33:58
Hermes as Force H's anti-submarine carrier
A Hermes air group weighted toward Swordfish could have supplied Force H with a dedicated anti-submarine screen.