Their about page (https://edhgen.ai/about) implies they are using an algorithm that plays games of magic to train the AI against known good decks. Which will give no insight as to why it includes a card, but will take into account all the utility side of things. Or is will to the extent that it's game playing engine can make strategic choices (which it probably can't)
LovesTha
Yes, but if you have multiple armies (hence the need for changelings) you can pick which of them get the counters.
Those two commander options are different cards, I'd probably make that change too.
The biggest reason to go out of LotR cards would be to put in some changelings so you can use the amass to pump many creatures instead of just one. Inside LotR I don't see many ways to cash in on having a giant Army.
Requesting [[Sauron, Lord of the Rings]] [[Sauron, The Dark Lord]]
What I like least about using Ancient Brass Dragon is that the die roll starts the decision tree, so the card takes a long time to resolve each time as the owner can't easily decide what to get before it triggers.
+1
With replacement effects the affected player chooses which of all applicable replacement effects to apply first, then after applying that they check if any others need to be applied. Once there are no more applicable replacement effects the modified effect happens.
Clearly mtgzone needs to rebrand as ɱ