Like I said, if Chang had hair you would see no ridges. Those ridges would be under the hairstyles of TOS Klingons.
And yes I read Justman's memo and and you seem to be quoting from the CBS article that circulated it rather than the memo itself. He was very specific that the Starships (the Constitution Class as it is now known) were the only ones to have the arrow insignia. Outside those couple of uses, everyone we see that we know works for the fleet and not stationed on a ship wears the flower emblem (regardless of rank). That young woman in the last image is likely regularly assigned to a Starship that is in for service and is either on temporary assignment or there for some other purpose. In reality those images from Court Martial were just recycled Enterprise crew uniforms and not a deliberate show of what emblem the production team intended them to wear. We actually never see another ship crew member in any other episodes sporting the arrow. And we only see Decker, Tracey, and Tracey's CMO sporting a different emblem in TOS.
The Antares crew was cited in Justman's memo to cement that the arrow was only for the elite 12 (or so) Starships. But the belief that each ship should have it's own emblem was born out when Enterprise gave the Defiant its own emblem and basically cemented that idea that Decker and Tracey's emblems were not mistakes. Canon is not based on the intent of the producers, but by what ended up on screen. So this conversation is based on 4 episodes, three of which support multiple ship emblems for Constitution Class ships and one episode that shows the arrow on other ships. The converstion wasn't ended by Justman's memo. It was only circulated to support the use of it as the fleet wide emblem in Discovery (which the memo actually does not support and which isn't canon by TOS, TAS, TMP, or ENT). The TOS Starfleet wide emblem is the other one that we see on the side of the TOS Enterprise and on the wall behind so many flag officers. And the flag officers and midshipmen wear flower insignias and not the arrow. Yet another way that Discovery has tried to rewrite canon.
There are several possible explanations that can make the three TOS episodes and the one ENT episode agree. But the one suggested by the Discovery producers is not one of them and is not supported by anything made prior to 1982's TWOK when the arrow did become fleet wide and at all levels and on all ships. Prior to that, every non-starship character in a standard uniform wears a flower emblem and there are 3 TOS starship emblems and one from ENT and one from TAS. This continued through the Epsilon 9 crew in TMP.