The closest example I’ve ever seen is Cayde in the ‘Gunslinger’s Last Stand’ FMV where he’s fighting the Scorn. He goes from straight up Golden Gun to Way of a Thousand cuts in virtually the blink of an eye, and even then they are both apart Gunslinger subclass. With the exception of Zavala who is portrayed as a Striker in the Destiny 2: Zavala Story trailer, and later on is a Defender at the start of Red War campaign, most, if not all of the famous named Guardians tend to stick to one elemental ( Solar, Arc or Void ) subclass, and tend to specialize in one particular Class Tree.