You will never see me defending the Devastator or the Vindicator. But I was chiming in on a discussion of the Skua vs. the SBD which was already ongoing. Pointing out that the Skua was a terrible aircraft by comparison to the SBD, in contrary to what some were claiming, may be low hanging fruit, but it apparently needed to be pointed out.
By the time the Skua was retired, most front line combat aircraft flying on both sides in the Battle of Britain had already been fitted with some armor and some kind of self sealing fuel tanks. So the necessity of doing this had been recognized and implemented with other aircraft. Nor were the British the only people to realize that these were needed. The French also had several aircraft with these protective features flying and fighting during the Battle of France - the D.520 fighter, Br 693 fast bomber and Potez 63.11 had armor and self sealing tanks. Many Soviet aircraft, like the later variants of the I-16 fighter and Su-2 bomber were already being fitted with armor before the Battle of Britain even started, based on combat experience in the Spanish Civil War and in Manchuria. The LaGG-3 and Yak 1 fighters and the Il-2 and Pe 2 bombers (all introduced in 1941) all had at least some armor, which was later enhanced.
Armor and self sealing fuel tanks were not necessary for training flights in the US in 1940, but the Americans were already starting to fit armor, bullet proof glass and self sealing tanks to aircraft being sent to France and Britain before the Skua was retired. Once the war started, most of the USN and USAAF combat aircraft had both fairly heavy armor and self sealing tanks, (considerably better protection in fact than the aluminum "armor" on the fuselage fuel tank of a Hurricane or Spitfire at the time). Important export aircraft such as the Tomahawk IIB, in action with the RAF in 1941, had both armor and self sealing tanks.
Most Skua units were equipped with the Fairy Fulmar when the Skua was retired.
According to "armouredcarriers.com", the Fulmar had at least one armored and self sealing fuel tank between the two crew positions, and the pilot had a bullet proof glass windscreen, but no armor behind his seat, and the navigator also had no armor of any kind. If that is correct, I would call that inadequate for a combat aircraft at that time. Did the Fairey Swordfish have armor or self sealing tanks? I was unable to find any reference to it. Same for the Fairey Albacore.
I would say that luckily for the servicemen of the FAA, the Skua was quickly retired, and though the Fulmar, Swordfish and Albacore soldiered on, they were soon augmented by more capable aircraft such as Martlets and Avengers which were better equipped for positive outcomes during encounters with enemy aircraft.