From another Alumni of HOUSE OF MYSTERY and other DC mystery titles, Alfredo Alcala would have been another interesting choice. A number of his anthology stories in the various DC mystery titles could be seen as Swamp Thing stories with a few story elements changed.
You can somewhat see what Alcala would have done from his work on
MAN-THING 14, a single issue Alcala penciled and inked (at a glance I'd guess the cover is by Gil Kane/Klaus Janson).
Alcala also did a nice 30-page story in
GIANT-SIZE MAN-THING 3 (some day I'll be able to avoid giggling when I write that title!) that also demonstrates a sampling of what Alcala could have produced on SWAMP THING.
Alcala also a decade later inked a number of issues of SWAMP THING during the Alan Moore run, and into Rick Veitch's run that followed it, I like Alcala inking Alcala, but not really on anyone else, with the rare exception of John Buscema, and a few others.
I especially liked Alcala's work on SWAMP THING 45, "Ghost Dance", a great single issue story of the Alan Moore run, about a mansion with countless rooms added on by the surviving widow of a gun manufacturer, to house all the ghosts killed by her family's manufactured guns, and the sound of construction hammers a metaphor sound for the gunfire that made ghosts of them. "The sound of hammers... the sound of hammers must never stop..."
