I wanted Engineers to be able to build Railroads (which normal workers cannot build) as well as some improvements like mines and windmills. Engineers still have that ability if they are left with UNITAI_ENGINEER, but then they cannot be automated to build anything and more importantly cannot built a Route To another tile. Using a unit without UNITAI_WORKER as a worker involves a lot of micromanagement.
According to the Lore, Eurabatres is described as "the most powerful creature of the created." Presumably this only means those beings created by The Twenty-One rather than The One, as it would be odd for him to be more powerful than the god who created him, but it is still pretty impressive. The Gold Dragon is much closer to a god than to a mortal being. Eurabatres is the original dragon, the result of a completely new idea on the part of Amathaon. All other dragons are but poor reflections of his majesty. Most of the gods made multiple dragons (Bhall had dozens if not hundreds of fire dragons serving her, but none were greater than Acheron and the lesser beasts have been vanquished and forgotten) as well as several other great beasts to serve as their weapons in the Godswar, which involved expending their own power and spreading it more broadly. (Agares did not create any dragons, beasts, or demons, but he has corrupted enough that were made to serve the good gods that his army is the strongest in every category.) Amathaon made only one, but concentrated so much power in him that he alone could face entire armies of his foes. Eurabatres is also the most intelligent of the dragons. Most of the dragons are simply weapons of mass destruction that follow whatever orders their god gives them. Amathaon so disliked fighting that he delegated all of the decisions pertaining to the war to his dragon. The Golden One was made to give orders rather than take them, and has an unparalleled strategic as well as tactical genius.
If anything, Eurabatres's power is underrepresented compared to the other dragons. I didn't want to risk making him greater than Auric Ascended though.
Nothing can compare to djinn for now. And I never got late game tech past strength of the will, you've boosted tier III units like mage too much, and AI can never use them well. Even in deity, many AI stay backward in tech (maybe they got too many cities and units), while Lanun often advanced but still got only 1 SOD. AI tends to have too many units....