I imagine...Lister is the scarecrow due to his raggedy appearance, while Rimmer is Dorothy purely for the humiliation and good use of squeaky-voice. (tinman and cowardly lion are obvious of course).
Holly for the wizard?
(Holly for the wizard?
ferret -> twitter.com/syfyautocorrect <-,
Sat 12 Jan 2013, 3:31,
archived)