A point to consider is that the Brits. historically tended to go on the theory of a routing ships with less significant escort resources; especially in the earlier years.
In the Med., the significance of the occupation of the island of Malta was the "hinge pin" of the ability of the Allied forces to maintain shipping routes and coverage to much of North Africa, the Med. & oil resources in the Mid-east,
"There was no lasting solution for the enemy short of the conquest of Malta."
, P.M. Winston Churchill
Historic attempts to reach the battered Allied forces holding out on Malta:
Operation Harpoon: mid. June '42
Operation Bellows: early Aug. '42
Operation Pedestal: mid. Aug. '42 (considered successful... despite severe losses)
(check in on the significance of escorts provided in Op. Pedestal!... WOW!)
Air support following Allied progression in Med. (retaining Malta's airbase & harbor, N. African Allied forces pushing against Rommel, etc.) provided more coverage. Other naval events thinned some of the more significant escort deployments to the Med. as well.