There are many studies that show some moves or features of the golf swing that are supposed to be common to all great golfers. However it seems you can always find a swing that is exception to the rule. Showing that these rules are not absolute. At least in classic golf game, where precision is the main point.
For example, here is a video that shows some of the weirdest swings in professional golf that go against almost any rule out there of a so called standard golf swing. Amongst them Jim Furyk's and Eamonn Darcy's "chicken wing" swing, Jim Thorpe's helicopter follow-through, and, Josh Broadaway's cross handed swing!
Almost, yes, because there is one common denominator that allows no exception to the rule, and that is: sweet spot precision. There is no top player that hasn't mastered it.
At 5:15 in the video above, Peter Jacobsen (22 professional wins) comments: "...just goes to show you it doesn't matter how you're taking back, it's how you make impact on the golf ball."
Tom Stickney posted an article at GolfWRX where he tested golfers of various handicaps for their impact precision. Below are pics of their impact locations—5 shots each.
PGA Tour Pro
The lower the handicap, the smaller—and closer to the sweet spot the impact pattern. No exception to the rule here! To improve your scores, improve your impact location!
Impact location test and impact location images by Tom Stickney. Retrieved from http://www.golfwrx.com/167927/impact-location-by-handicap/