They were all procured as part of a competition to find replacements for the SB2C and TBM. The idea was to provide one aircraft to fill the dive bomber and torpedo bomber roles (BT). The little known firm Kaiser-Fleet Wings was involved because the Navy wanted to source the aircraft from manufacturer's that weren't tapped out by wartime production demands. The Douglas BTD started out as the second aircraft pictured and changed to the third aircraft when the Navy decided it only wanted single piloted aircraft. The Navy ended up placing orders for 300+ BTD-1s but this was reduced to 28 when the war ended. These 28 aircraft were quickly supplanted by two follow ons to the BT competition that ended up beating out the Curtis XBTC:
Of these two aircraft, one would be known as the "Awful Monster" and, although capable of lifting tremendous loads, was derided for it's handling capabilities at the boat and was quickly supplanted fleet wide by the "Able Dog". So, there's a good reason that all the aircraft pictured look like Skyraider derivatives; in a sense they were.