The Grumman A2F (A-6) Intruder was the result of a February 1957 Navy request for proposals for a replacement for the Douglas AD Skyraider in both the Navy and the Marine Corps.
The Ling-Temco-Vought A-7 Corsair II was the result of a May 17, 1963 Navy design competition named VAL, which stood for Light Attack Aircraft.
The VAL aircraft was to replace the Douglas A-4 Skyhawk, and was to have as its primary mission the delivery of conventional ordnance as opposed to nuclear weapons.
The requirement specified that the aircraft would have to be in service no later than 1967.
Remember that the Navy was operating the Essex, Independence, Midway, Forrestal, Kitty Hawk and Enterprise classes of carriers when those planes were designed, built and operated.
Both were piles of shit, hard to work on, non-existent spare parts, crappy designs, they were junk.
Both were sent to the boneyard because their wings could not handle the stress of dropping bombs.
The A-4 Skyhawk outlasted both of them.