Why make the CAPTAIN rank one with a broken line of braid?
Good question; by the time that braid appeared, the show had already settled on a complex pattern that was only "less militaristic" in the sense that it omitted one braid from each USN or RN cuff set... It wasn't vague or futuristic or anything. And yet there is this anomaly on Kirk's sleeve.
It's only anomalous compared to the RN/USN stripes, though, because they go from three to four, skipping 3.5 stripes. Sequentially, the Starfleet system makes more sense that the RN/USN system. (The reason they skip 3.5 is because originally there were no narrow stripes, just one through four regular stripes for lieutenant, commander, captain and commodore. Later they moved commodore up to the big flag-rank stripe, bumped the rest up, and added some half stripes for new grades without changing the existing stripes.)
I've always wondered, though, if the broken stripe was the reason we saw only one JG in all of TOS; the vast majority of background personnel have either one stripe or none. Might it be that it was just a lot easier for wardrobe to machine-sew single stripes on the sleeves, rather than lining up, spacing, pinning and sewing on several small bits of braid? Of course, principal characters would be different, but for background players, why go to the added trouble?
Perhaps his broken braid is there to emphasize how junior he is? That is, not a stuffy old four-braid skipper, but some sort of a skipper-in-training?
The British RN used to make a seniority distinction between captains: those under three years were equivalent to an army lieutenant colonel, after that they were equal to colonel. Wouldn't a senior grade of captain in Starfleet be a good slot for the much-debated fleet captain?!
I never really cared for the collar pips as being somewhat small for recognation at any distance, but I have to admit that aboard a starship recognizing rank from far away would not be much of an issue. I would have preferred, just for a nice continuty, that the TNG pips had followed the came sequence as the TOS sleeve braid, so two solid and one voided pips would be the insignia for Capt instead of LCdr. And I much prefer the pips to the flashy, arbitrary rank pins of the ST2-6 movies.
I also liked the idea of individual ship emblems, and I think that was the basic intent, even though that did not always carry through to the execution. If I had one wish about TOS uniforms, though, it would be that they showed some type of grade insignia for enlisted personnel.
--Justin