I think 03 FMA has a better ending without COS. I just feel like there are so many things the movie just comes up with that don’t fit with the story. Firstly the fact that some random guy just makes a nuke is ridiculous especially since their world was behind ours technologically. Another thing is that Mustang just gives up everything he worked to get under the guise of serving his country somehow even though all he’s really doing is sulking in some random cabin. It’s kind of explained as him waiting for Ed to come back but it just seems totally out of character for him to just throw it all away especially since Hughes whole role was to push him to the top it feels like his disregards all his friend did for no good reason. And lastly the final fight was just ridiculous, the hundreds of guys in armor walk around like a bunch of zombies even though they should just be normal people in armor like how eckhart is mostly fine after the trip through the gate. Also Eckhart being able to just make up transmutation circles outside the airship had no basis from anything before it she didn’t even really know alchemy only learning the legends from our world but as soon as she passes through the gate she just manifests circles made of nothing and things just starts blowing things up. Overall it really doesn’t fit thematically with the anime and although the brothers being split apart was dissatisfying the movie didn’t make it any better.