I like the non-action better, but if the author wants to flex their drawing muscles for a few chapters, that's OK.
It kind of accentuates the difference between the dragon lands and normal school life.
Just because the story includes outlandish concepts for our reality doesn't mean you can make the story do backflips into different genres in the span of one chapter. Half dragon girl goes to high school is a very different story than half dragon girl fights dragons. This fight scene is giving me whiplash.
It's like if dragon ball went from a slice of life of Goku and his grandpa for 40 chapters to suddenly fighting against Piccolo.