I didn’t ignore what you said concerning the fire range - the movie also establishes that the First Order probably could have, at any point, jumped ahead and just wiped them out, but Hux instead chose to just follow behind and essentially torture them instead of just getting it over with. He’s being sadistic and awful and enjoying it instead of putting in the work.
Which is ALSO a thematic element that keeps getting referenced and paid off later in the movie - the villains’ hubris and arrogance gets them ruined. Had Hux been as ruthless as he pretends he is, the movie would have ended after 30 minutes. Had Snoke been paying attention instead of feeling himself, he wouldn’t have gotten bisected. If Kylo had been paying attention instead of raging out on Crait, he would have figured out what was really going on before it was too late.
Here’s a larger point that I’m trying to make - aside from the fact these “plot holes” aren’t really plot holes at all, if your deconstruction of the story is being done solely to point out how there are ways to effectively end the story after 30 minutes because the bad guys “could have” done something else that they didn’t do and it would wipe out the good guys, then you’re not really worried about the story or the plot-holes, you’re basically trying to invalidate the movie, period. That’s not fixing a story, that’s anti-storytelling. That’s suggesting that our heroes need to be so pigeonholed BY the plot that the course of action they take is the only possible course of action they COULD take. That’s video-game routing, not large-scale movie storytelling. What’s the end goal of this criticism, and what is it that it’s saying about the story and the characters and the themes and ideas they represent?
The rate of cannon fire and the distance on that cannon fire isn’t important enough to invalidate whole themes and arcs, and suggesting the story needs to work that way in order to be successful doesn’t make any sense to me. Especially not in the face of how clearly the film DOES communicate all its ideas and details as they’re happening.