Which actors who played Imperial officers, other than Mark Jones, were ever on Dr. Who? I don’t believe Tom Mannion was. Michael Culver wasn’t. Was Leslie Schofield, Julian Glover, Pip Miller, Alan Flyng, or Michael Sheard on Dr. Who?
Leslie Schofield: The War Games and The Face of Evil
Julian Glover: City of Death
Michael Sheard: The Ark, The Mind of Evil, Pyramids of Mars, The Invisible Enemy, etc
Not sure about the rest, may just be failing Google-fu or uncredited appearances. Certainly it’s probably more fair to say that Imperial Officers were on Doctor Who a surprising amount of times, not that all of them were.