I think I have both...will try origins first based on what you said
I played both. I actually played Odyssey before Origins.
Origins combat feels a tad heavier than Odyssey. I love the shield in this game and the blocking mechanism with the dual blades (daggers). Origins weapons from an aesthetic standpoint like way better than Odyssey weapons. Odyssey does have a better build system than Origins. Origins tools and poison mechanics felt better than Odyssey. Also, I like how your eagle shows the status of people in the world and the animals, downside his detection of enemies feels way slower than in Odyssey.
The Mercenaries and Commanders are way tougher in Origins fighting them feels really satisfying and challenging.
The way that AC: Odyssey tells the story through cut scenes and multiple branching choices was a nice addition versus how AC: Origins tells the story.
Yet, AC: Origins story so far feels much more emotionally invested more so due to Bayek situation with his family. Origins has the cool ass assassination cut scenes, Odyssey doesn’t due to the sheer amount of assassination you have to do.
Origins doesn’t have many naval combat instances as Odyssey does but Origins felt much more cinematic and fun.
Odyssey has the Mythic hunts and the Sparta vs Athena battles which were really cool, in retrospect. Origins has the hippodrome races and gladiator matches that were really good as well.