Do I have to start every single sentence in a post with "to me" or "imo"? It should be very obvious that the whole post is based on my subjective opinion.
Anyway, back to topic?!
Starting the statement with imo wouldn't change anything. None of us are Sapkowski and should not presume we are qulified to say who Sapkowski should or should not name as an official artist for his works. Anyway, as you said, this is going off-topic.