To be fair, I don't think they built Swarm from scratch, I think it is/was a rebranding of an acquired product. That being said, Docker and swarm in particular move too fast for their docs to keep up (let's change the syntax for some important commands between the final RC and the release?) and it feels like the only way to be well informed is to scour the github issues, which seems wrong for something that's touted as a stable, commercially-supported product.