Sounds like you both have never played yuriko.

Funny you should say that. While I don't actively pilot Yuriko currently (not sense ye olde Yuriko Doomsday days) one of my local pod members does. It's one of the CEDH decks I've played against the most, and I've piloted it a decent number of times in deck swap games over the past year.

Trust me they are different

There's nothing that's inherently different between the two decks at a core strategy level that I can see. Given the sheer number of overlapping cards you have to admit that there's a decent chance that you'll start with an opening hand that could come from either of the two decks and would play the same way. Especially since I don't see anything in the 12 cards you swapped that hits my radar as a card you might try to pull with a mulligan or that would be a high priority tutor target.

As far as the specifics of those 12 cards, looks like you're trading out several of your silver bullets and value cards for more creature removal, a slightly boosted creature count, and a higher ninja count. From the perspective of an opponent you do seem to be removing several of the cards that have given me trouble in various games. Metallic Mimic is one card that catches my eye, since it turns off the effect of Tetsuko I don't think I would include in personally.