Yes, Stand and There's A Riot Goin' On are great albums, but Sly was a master of the single. His songs belonged on the radio and to the radio.
His ability to distill his ambitions into three and four minute explosions of joy without getting corny or preachy came from his ability to kick his band's butt into overdrive. He went crazy as a result.
Or was it the craziness that gave him the results? I think we've got a chicken or the egg theory here.