In fact, logically, Oden must be YOUNGER than Zoro right now. Cause according to Kinemon before. Oden became the Daimyo of Kuri at age of 20. I have serious doubts that Oden is now a Daimyo in the beginning of flashback. He STILL will be banished from flower capital by his father, and then go to Kuri, do all good things there, and then he will become a Daimyo at age 20.
Oden in reply to some others who said Zoro tamed Enma at younger age than Oden. Logically, following the timeline, it's the opposite, Oden is the one who tamed it at a younger age. Cause if he didn't tame Enma, he wouldn't have the sword on his waist. Cause Kinemon stated that a swing from the sword is enough to make you unconscious if you cannot tame it and control your Ryuu with it. Unless oden is stupid and carries the sword regardless LOL, I doubt that