Jamie,
Good article. I'm not a DBA, but rather a programmer and have never read Kimball nor heard of Kimball. However, one thought occurs to me as we were attempting to model something like this. Your theory is correct from a programmers point of view, DRY -> don't repeat yourself. But what happens when the two pieces of data are not contiguous.
In other words, using your example, what if your "customer", or "employee" Henry left for a while and then came back. He is the same person, so you would naturally use his same id again, but he definitely wasn't effective while not being at the company. Anyways, just a thought.