The historical strike scored five hits from eleven torpedoes, so the planned forty-two-aircraft attack offers a useful intermediate counterfactual before the four-carrier scenario. Allowing for several unserviceable aircraft still leaves about twenty torpedoes in the two waves. A conservative projection gives roughly ten hits, with Vittorio Veneto and already damaged ships presenting plausible targets. Giulio Cesare's protected anchorage made her difficult to reach by torpedo, so concentrating Skua dive bombers offered the more plausible route to damaging her. Repeated hits could have turned temporary damage into permanent losses even without assembling four carriers.
Notable Point ยท 46:39-49:36
The unrealized two-carrier damage case
Even the original Eagle-Illustrious plan might have doubled the historical torpedo hits and permanently disabled more Italian battleships.