I would like to disagree to the extent that I find Nigel Planer’s Rincewind to nail the character in my mind. His reading of
“The Last Continent” with Rincewind vs the various Australian tropes is a family favorite.
If you see the Hogfather screen adaptation he plays the role of the wizard Sidney.
I don’t know how close he was to Pratchett - but he has recently written a novel that supposedly was influenced by Discworld[1] (but not of Discworld)