I recall many segments were animated by the Hubleys for The Electric Company, including "True Blue Sue", "Low Down Clown", "Glad Gladys" and most notably the Letterman segments.
I also learned that Bruce Cayard animated some inserts for The Electric Company too. The only one that comes to my mind is the one with a girl named Myrna.
I believe Al Jarnow animated the "Why Me?" song segment, as the words displayed use the same lettering style as the "Yakity-Yakity-Yak" and the "man demonstrating up and down" segment - both from Sesame Street.
I wouldn't be surprised if Jeff Hale animated the "Right on!" segment. I believe many early segments Hale animated involved African-American characters, like in "J for Jacket, Jenny and Jeff" and "The Yo-Yo Master and the Lost Kid" segments - again, both from Sesame Street. And this was long before the Ringmaster and Consonant Sound segments which involved Caucasian characters.
Do you suppose that the reason why the animators for Sesame Street also worked for The Electric Company, is because their contract to animate for those shows is for the Children's Television Workshop and not just specific individual shows?