I'm of the Presley/Beatles generation. Not listed among the choices, unfortunately, is Harry Lillis "Bing" Crosby, Jr., who is actually the king of pop, with 41 number 1 hits, and an astounding 383 ( ! ) in the top 30. At one time in the late 40's, Crosby tunes filled an estimated *half* of the air time devoted to music.
But when you ask "Who's bigger in music history?," its fair to include non-performance impact, and Crosby gains points there because of his innovative use of the microphone, his involvement with Ampex, and his pre-recording of radio programs (so he could go out and play golf), all of which altered music history.
Just as an aside, Crosby's rendition of "White Christmas" -- during World War II when our men and women were fighting in Europe and the Pacific so that we could be here today discussing such things -- became something of a second national anthem. It made everybody think of those they couldn't be with.