I’d say he’s more like Cherenkov, a senescent figurehead placeholder till the real string man can be appointed.
Actually Chernenko was Brezhnev designated successor. Right hand man to Brezhnev. He became the chairman because they (Brezhnev clique) wanted to extend the Brezhnev era without Brezhnev. Andropov kind of sneak in, trying some changes, Chernenko was put in charge as reaction to his actions. He looked healthy when he took over. They hoped for him to last a lot longer. I see Brezhnev and Cherneko being basically the same.
When he Chernenko died, the system finally started to crumble.