(Despite the obvious similarities and the fact that Vernon Wells played both characters, I can’t seem to find any tangible information that they purposely modeled the Lord General in Weird Science after Wez in Mad Max: The Road Warrior from four years prior.)
(I couldn’t find any information about Seth MacFarlane specifically basing American Dad‘s Stan Smith on Robert Z’Dar—especially in Maniac Cop—but the similarity is obvious. I have seen Family Guy mention Robert Z’Dar, so he definitely knows about him, but that that doesn’t prove anything, maybe he became aware of Z’Dar after someone pointed out Stan Smith’s similarity to him later.)