The Amazing A-Man, had recently commented on a post on Zartan, mentioning this;
I was watching some video of a convention appearance with Ron Rudat and some fan guys presenting, one guy mentions Zartan and siblings had the shoulder armor because the flesh color change plastic wouldn’t have worked for the shoulder construction due to its softness or something. Zandar and Zarana were originally going to have bare left shoulders with matching dragon tattoos.
Interestingly enough, in European Markets, under the Action Force banner, the original Dragon Tattoo art was used on the cards. They also edited out the weapons the characters were holding, as well as making Zarana far more risqué.