In the newer show, “Liv and Maddie,” Maddie is a star basketball player. “Liv and Maddie” is a gentle, moderately amusing comedy that arrives Sunday on the Disney Channel, and it’s a good one for grandparents to watch with their grandchildren.s. Duke played identical cousins, one a sophisticate with a British accent, the other a classic American teenager from the early rock ’n’ roll era. The setup of “Liv and Maddie” is a bit different — the title characters are twins, both played by Dove Cameron — but the dynamic is the same.