This is a good question. I wonder if there was an "original" bearded, short, older comic western sidekick who proved popular enough that all the studios cast their own imitation. There certainly were plenty of them in 1950s Western comics. I think the underlying notion behind all movie western sidekicks was to find someone as much as possible the opposite of the hero. Hero: serious, handsome, tall, young, intelligent, proper, physically fit, clean, effective, brave. Sidekick: prankster, "funny-looking," short, old, dumb/clueless, indecorous, scrawny/fat/weak, dirty/shabby/rumpled, bumbling, cowardly. Fuzzy St. John and The Cisco Kid's Pancho were the same character in different bodies.