Headscratchers / Star Trek S2 E6 "The Doomsday Machine"

• Why was Commodore Decker commanding a starship? As a commodore, isn't he supposed to be retired from that line of work, hence why a lot of the main characters make such a big deal out of not wanting to be promoted and preferring The Captain's chair to a job where they are merely paper pushers. In The Ultimate Computer, however, Commodore Bob Wesley was commanding a squadron of four starships which is in keeping with what a naval commodore might do in wartime. But most commodores are part of an Admiralty's support staff and even during wartime, spend more time on the flagship or command ship than anywhere else. Starfleet appears to treat the rank of commodore as among the flag ranks so why was Decker in command of a single starship presumably on the usual exploration mission (the Constellation not being a designated flagship so there's no indication that it was on any special mission requiring the presence of a flag officer) when he's supposed to be part of the "top brass"?
  • "Commodore" can be an "in-between" rank from Captain to Admiral. Typically, a Commodore would command a small fleet or task force, but most of the Commodores we see in TOS run starbases, and the rank seems to have fallen into disuse by the time of TNG. One could infer, from Discovery, that losses from the Klingon War are still being dealt with, so Commodore is more prevalent rank, qualifying an individual for anything from Captain of a single ship (presumably with command authority over any other ships in the area, "I need help, I'm a Commodore and you're a Captain, get your butt over here!") to installations important enough to merit what is technically a flag rank but not important enough to tie down an actual Admiral. Then there's the potential of "Commodore" existing largely as a ceremonial rank, a title you call someone who holds the rank of Captain but is not The Captain of the ship they are aboard (to eliminate confusion in critical situations about who is in command). One could speculate that by the time of TNG, the ranks were more completely staffed, and Commodores simply weren't needed anymore, anyone with the right skills, experience, and mindset went straight from Captain to Admiral.
    • To confuse matters, TOS also had the rank of "Fleet Captain" where they were still addressed as Captain. There were Garth of Izar and Christopher Pike (at the time of The Menagerie). It wasn't clear as to whether they were Captains at the same rank as Kirk but with an honorary addition. Or whether it was an actual rank between Captain and Commodore. The term Fleet Captain could either mean "Captain of a fleet" or "Captain in a fleet" as in being short for "Starfleet Captain". But that would seem superfluous.
• Why was Decker allowed to take command of the Enterprise when he was just found in a near-catatonic state with obvious PTSD? A full psych workup shouldn't have been necessary to relieve him; it should've been necessary to clear him for duty before allowing him anywhere near the bridge.
  • He was orientated to time and place. He seemed to shake off the state he was found in by the time he returned to the Enterprise, so it would easily be put down to fatigue which he shook off. He gave every indication he was sane and alert, and therefore presumed to be so.
  • McCoy did try to disqualify him.