Kozuki clan are secret D's like Laws family.
Also they share way different dreams. While Oden just wants to explore the outside world because he had been locked up in his country since birth and didn't have a clue about anything, Luffy was inspired by Shanks and Roger to become the Pirate King and the most free person in the world.
Oden loves the kick of adventure and getting to know new islands, places, people. He wants to see how various human life and the world can be, and not be restricted by Wanos law. He is ready to serve under Whitebeard and just be one of the men, while Luffy would agree to plans and (try to) follow them (and mess them up eventually) but would never want to work for someone.
Oden easily fell in love with Toki, they had children on their journey. Luffy would never have such thoughts. That's because of the difference in their dreams. They desire a different kind of freedom. Oden doesn't want to stand on top, he wants to see. Luffy sees along his way, but he wants to be on the top.
Oden is rough, unlike Luffy who has much more of a kind heart.
Even if they are really similar I wouldn't call him the samurai or Wano version of Luffy. I am pretty sure Oda is aware of their similarities and tries to make them similar on purpose so the prophecy is being handled by someone who reminds one of Oden, and shares similar dreams and strength and willpower.
But Luffy and Oden are still way different and are their own character with their own purpose. So I can't just say he is the Samurai version or Wano version of Luffy.