Glad the intent is apparent; the box art is my favorite too. William George and Rudy Obrero did incredible work. The box art was darker and moodier than the Filmation cartoon. Some of the brighter MOTU stuff was cool too, like the paintings by Earl Norem and Esteban Maroto.
The MoTU franchise is interesting in that you can see it's evolution in character development throughout the early toy and comic art up until individual personalities get established with the Filmation series. There's such an untapped history to that early art that definitely has a distinct mood to it.