If there's a problem with this battle it's more because it's a manga adaptation who takes multiple volumes to adapt one volume from the Light Novel.
At least the mangaka understood the importance to have the "secondary characters" in the manga, unlike the one who drawing So I'm a Spider so What?'s manga.
So the anime is supposed to be a dumpster fire but the manga is still quite solid imho? Is Mothersbasement just wrong or did they mess up the animation?