Why were Albert Dussel and Van Dann used in the play The diary of anne frank?

Van Dann was not a real person, he is a fictional character created for the play and television series to depict the Van Pels family. The Van Pels family was portrayed in the play by Hermann and Auguste van Daan, who were their actual names. Albert Dussel, known as Fritz Pfeffer in real life, was a German dentist and a Jewish refugee. He moved to the Netherlands and during the war, was part of the group that was hiding along with Otto and Margot Frank, Hermann and Auguste van Pels, and Anne and Peter van Pels. It is believed he was in the secret annex from November 16, 1942, until August 4, 1944.