Another artist who is, I think, often overlooked and discounted but very creative, is Tom Sutton. Sutton excelled on horror and science fiction anthology stories, much more so than on superhero stuff. His style is at once loose and sketchy, but also ornately detailed and decorative. He was more of a Marvel artist than a DC artist.
But I actually think he did the bulk of his work for Charleton, possibly for the freedom and lack of editorial interference working there allowed. Or possibly because there was just more work in the mystery/anthology and s-f genres he preferred.

From
CREEPY 64, August 1974, the story "Autumn at Arkham", Sutton exhibits the hybrid of science and the supernatural that would have made him a good pick as a replacement on SWAMP THING.