The "dog bone" clasp link vs. the "u shape" clasp link

[Eric88]

This is pretty insignificant in the grand scheme of things, but I have a couple of different "pre-ceramic" Rolex bracelets and noticed that some have the "dog bone" link right next to the flip-lock clasp, like this. Picture borrowed from a great jacek shot on the 93150.



While there is another variation with a "u" shaped end link such as this on the 93160.



Both provide the same function, but the second is more visually appealing to me as it looks like one of the other links more seamlessly integrated with the clasp. Anyone have insight on whey Rolex sometimes used the dog bone vs. the u-shape link right before the clasp?