This is a really good point Tom. I have routinely confused Otey/Seitz and Guiheen/McCauley over the years.
As a possible counterpoint, T206 artwork of Danville pitcher Fleet Mayberry in a pitching pose was prepared, but not issued.
(Although I suppose this could also be understood as consistent with your thesis about favoritism toward portraits).
http://t206resource.com/Olbermann%20Proofs.html