Some of the earliest undergrounds were more quintessentially EC than EC was. Insect Fear, Skull. Thrilling Murder, were all able to walk through the door that EC had tantalizingly opened just a crack. By the way, did you ever see that huge painting of Larry Todd's (released as a poster) called Moby Gleep? Insanely beautiful.
Wonderful analysis! Added Moby Gleep and that, in turn, made me add the great Todd cover from Eerie #33 (Warren kinda stepped through that same door)