I'm not sure about this, but it seems to me that Wood learned a lot from his work with Eisner on the Spirit. I'm no expert on Wood -- his life and career are too depressing for me -- but I see, rightly or wrongly a significant difference between before and after the Spirit gig. Not that he copied Eisner or anything but *something* changed or developed or matured at that point.
No expert nither, but I thought the maturity of his craft came on Weird Science BEFORE he did The Outer Space Spirit. You're right, though, this Avon stuff is before (or while?) the greatness switch turned on for Wally