Justin Baldoni and Blake Lively's cast and crew agree there's conflict between the "It Ends With Us" costars -- but we've learned he's not the clear-cut villain, as some people who worked on the film are standing with Justin.

Production sources tell TMZ ... JB, who directed and co-starred in the romantic drama, is actually viewed quite favorably by a lot of the crew, as he was generally a nice guy to work with and cared a lot about the production.

Despite reports the cast and crew are rallying around Blake in the feud with Justin over creative differences ... we're told that's an overstatement.

Our sources say the truth is more like civil war -- there are definitely people siding with Blake, but there are also those who feel like Justin got screwed. While he's gone solo on the press tour promoting 'It Ends' ... we're told several people on the crew understand why.

For instance, Blake -- who produced the flick -- did hire her own editor and had her hubby Ryan Reynolds do last-minute rewrites on the script, even though this was supposed to be Justin's project.

We're told the creative struggle was obvious, at times, on set -- as we showed you one animated convo between Blake and Justin was captured by bystanders during filming.

The sources we spoke to felt Blake was eager to be seen as a creator, and that's why she tried to seize creative control of the film from Justin.

We're also told he's over the drama and looking to put it all in his rearview -- which is why he suggested last week Blake should direct the sequel.

As for all the stories about the on-set beef ... one source says cast members are milking the drama by design. It's called marketing.

The source pointed to similar buzz 2 years ago about director Olivia Wilde and her "Don't Worry Darling" stars Florence Pugh and Harry Styles feuding -- and that movie earned nearly $90 million at the box office.