Momoa was in a different movie entirely. They could have pulled it off - had there been any character that was a tonal middle-ground between him and EVERYONE ELSE it would have gone a long way to making the movie feel more dynamic and alive, less as a series of rote set-pieces.
On the other hand in the books Idaho appeared as so much of an outlier to every other person that "in a different movie entirely" seems weirdly fitting. You could even put Momoa in the Lynch version and it would seem accurate to the point of parody. The actual Idaho of the Lynch movie on the other hand, so unmemorable Lynch might have just written out the character entirely. The explanation given in the article (deliberately toned down to make the ghola version even bigger in part two) is an interesting excuse.
