Saying that two things are identical is saying that they are the same in every specific way. This is harder to demonstrate than showing that two things are dissimilar in one specific way.

You are using the Razor incorrectly. I don't care what you think you've said, I care what you've actually said - and what you've actually said is the following:

once we see that X and Y share a property, the simplest hypothesis is that they are the same

That is a false claim.