Cursive handwriting is standardized. This isn't like an interpretative dance. There's only one way to write an "l" in cursive, and when people deviate from that, it's for two reasons: 1) they gave up trying to write something legible, so it's just vague jerks in the right direction; 2) they approximate the shape, but they exaggerate certain features.
Otherwise, if you have 100 random Americans write out Barbara W Chandler in cursive, you're going to get almost exactly the same result from most of those people. Eyeballing it is dumb.
Comparing handwriting isn't about focusing on the similarities, because all people will approximate the same shape. They're always full of similarities. You need to focus on the differences.
With Barb's signature, what sticks out to me is that Barb has good handwriting. She sticks to a flat baseline, her characters are scaled properly.
Chris' signature is all over the place. It's sloppy. He doesn't stick to a flat baseline. One big problem Chris has is that most of his loops (for straight lines, like in lowercase D and H), are super big. He also overemphasizes the loops in his lowercase E's. Both of those are examples of him being sloppy. Like I said, Barb's is very professional and neat.
These signatures don't look alike, except that they're both cursive and somewhat legible. Ignore those aspects and the differences are easier to spot.