Some of your pictures are missing the scrnshot of EDDi, 1 is missing the Thargoid's rank, although I don't suppose it'll be different

.
But good work anyway!
Oops! Checked and Corrected. Though it doesn't make much of a difference, because you are right. They all rank as Elite.
The logs provided indicate all the goids involved were Elite, while I can see nothing much in common in their logos as indicated by the cockpit display. I surmise that the hypohesis that the goid logo denotes their combat rank is disproved.
That's what it looks like.
But again there are no definite answers and large rooms for lots of speculation. If my theory is right and the ships are Thargoid workhorses left behind when they retreated, then the logos could still denote the rank of their former masters, they are just not up-to-date any more.
Obviously the Thargoids remain to be a mystery, wrapped inside a riddle, hidden within a secret.
EDIT:
Awesome study, commander. I think we can safely disprove the relation between the logos and the Thargoid's rank.
Thanks, actually it was cheaper than feeding them tons of Meta-Alloy credit-wise. The hardest part was flying the Eagle to the Pleiades, it's definitly not a ship suited for long range exploration.
There was also something else I tried to test: that the chemical burn marks visible on the wrecks are indeed caused by Thargoid weapons. I received the notification about the hazardous substance detected a number of times and even managed to escape after that, but every time the ship's hull remained clean of those marks. Also I got missile warnings twice, but my ship did not survive the impact on both occasions. So I can't say for sure if these missiles did have something like a chemical warhead.
No smoking gun verifiable that way.