It's pretty much Girl Boss the movie. Every female character is the best and baddest. The choreography is just dumb. You have battalion level strength with air cover, and armor and you lose to people charging with axes and laser muskets?? Yes the villagers have guns that look like muskets and fire one pew pew at a time.
The zombies in Dawn of the Dead were a bigger threat than a space faring war machine that has been at war for centuries?
I...half agree.
Although it's definitely English myth, Arthurian legend is so famous I don't mind a bit of tweaking. Similar to how I don't have a huge problem with taking liberties with Shakespeare. It's so big, a bit of tweaking can be fun...just don't piss on me and tell me it's raining, though; Don't tell me it's always been diverse, or whatever. Don't tell me "This is Arthurian legend now, and your interpretation is wrong."
Also, it's a Guy Ritchie action movie, based on Arthurian legend. I think when taken in that light it's fine...but I also get the objection on general principle to taking English/white cultural myth and adding any diversity at all, though. They'd certainly flip their lid if you did the opposite, so there's certainly merit to saying, well, we should probably gatekeep too then.