The cut makes weird dialogue edits, adds a silly Nari decapitation, and copy/pastes Duel of the Fates and Battle of the Heroes into places they don’t fit. The series does work and flow better as a 2 and a half hour movie, but I’d recommend other edits.
It’s not necessarily about working better as a movie, in my opinion. It definitely works as a series. The movie idea is a fantastic “what if?” that also works. There’s been a lot of great creativity around that idea.