Honestly there are some parts of the manga they shouldn't have cut out of the show.

Like Kiku attacking his big brother.

Or all the AmeLiet moments.

Even the Joan script. They had a lot more information on her and Francis friendship in the manga.

And there was a little (not much) but a little more of Fritz than there was in the show.

Not to mention, Yong (S. Korea) is a main character in the manga. He's not even in the show duo to S. Korean government not liking him.