It's overall hard to say how common or uncommon fights backstage are. Like Kurt Angle said a few years ago that Undertaker choked him out on a plane back in the day. But he didn't raise a fuss about it so it didn't matter. It wasn't news it was an anecdote.
I think for the most part there's not as much drama between the guys these days but who knows.
Wrestling is a really weird business in general. There's a culture of paying dues, receipts etc.