That's so much nonsense.
Kirk doesn't fight Khan because the actors' schedules didn't work out. Earlier versions of the script had them fighting it out.
Yep, it's customary for adversaries in a movie/tv series/book/whatever to face one another. That's neither a "trend" nor a "cliche," just an old, old facet of traditional storytelling. The folks who made TWOK were clever at working around their problem successfully, but painting it three decades later as some kind of innovation for which the movie deserves special recognition (unique?
) is apologetic foolishness.