After all, it has been revealed in both timelines that the king is not as noble as he may seem, having pinched the crimson toadstool from Charming during a Camelot quest and now pulling the wool over the Storybrookers’ eyes, even if it means sacrificing the occasional pawn along the way. “It’s a tricky one,” Kitsis noted, “because you can tell that Arthur and Charming would be best friends in another world. But Arthur is doing what he thinks is best for his kingdom, and Charming has to do what’s best for his family, and that’s going to put them at odds.” Added Horowitz, “Arthur isn’t a villain in the pure sense of villains that we’ve had before. What we saw is what we’ll continue to see — a man who’s really conflicted and is driven by doing what he thinks is right, and what he thinks is his destiny.”
http://tvline.com/2015/10/11/once-upon-a-time-season-5-emma-hook-breakup/
"If you go as far as you can see...you will then see enough to go even further." - Finn Balor