i dont think you know how model trickery goes, they spoke about this during WoD for the WoD feature cinematic they didnt have ANY of the warlord models so they literally got normal orc models and did fucky things to them to make them look likethe actual warlords, like literally spawning a wolf head in.
That is simply a tree model allready in game, with a fuck ton of effects put in, and simply moved forward to make it look much larger then it really is.
that is not a literal teldrassil sized model that they made and covered in fire effects then said "fuck it" that is literally just a normal sized tree they put close so it LOOKS like its far away and huge.
I am not going to look through all like 1000 tree models, but something like this could just be with abit of editing changed into that...
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if we arnt going to visit something why waste hundreds to thousands of man hours on making a huge ass fucking model for it?
when its much easier and looks much better to make a painting of it.