Seems sometime the text is mixing demon general and high ranking demon general? Because they say we can now easily defeat demon generals with the king-skill or Merus say they are still no match for a demon general. But a few pages before they were farming demon generals with just the meteor.
I rather like that they're using powerful strikes as an opening salvo. Outside of narrative tension there's little reason to hold back if you can one-shot the objective like that, and not have to worry about reinforcements or retaliation. i guess even that trope-aware squirrel god has given up on commenting about that.