Richter's repertoire small? He once said that his repertoire runs around eighty different programs, not counting chamber works! To quote Wikipedia: "Indeed, Richter's repertoire ranged from Handel and Bach to Karol Szymanowski, Alban Berg, Anton Webern, Igor Stravinsky, Béla Bartók, Paul Hindemith, Benjamin Britten, and George Gershwin."
Hofmann, was a great pianist, as was Horowitz. Sergei Rachmaninov, Arthur Rubinstein, and Dinu Lipatti too. Along with Richter they sum up the greats. Hofmann perhaps was a great technician (with his small hands and all), but sometimes used it in the wrong way. I have heard a few of his Chopin recordings that seem very rushed. As for Horowitz, there is something wrong with the way he presses the keys. Richter didn't just play the piano (as great a technician as he was), he communicated the notes, and in that way you could say he's not the greatest pianist, he was the greatest musical communicator of any pianist.