This whole battle was a mess.
1. The most important enemy was the queen locust, but MC didn't do anything to stop her. He stayed to struggle against weak enemies that was actually weak enough to be handled by the reinforcements that came afterwards.
2. Why did Art not know that those reinforcements were coming? Because they stayed at the back until after the queen locust attacked the stronghold. They ran to the frontline to escape, but acted like MC staying at the frontline alone was MC's mistake of not being able to trust others. Like they didn't ask him to do that in briefing.
3. Queen Locust one-shotted the strongest man in the kingdom while still in weaker form, but Urk blocked her attack easily even after she has unleashed her true power.
4. Queen Locust did nothing, just watching everytime Art and Urk did their skits.
5. Art for some unexplainable reason didn't unleash his power until he got "ordered" to.
So I guess nobody corrected this even after a year. The enemy saw through their plans, set off a nuke in the middle of the ambushing squad (which wasn't supposed to only be Art), summoned a bunch of high level monsters away from where the decoy squad was keeping them busy, and then just skipped herself straight to where the FMC is supporting the rear guard. That's 1.
2. The reinforcements were supposed to be sent to a different area, but the commander had a feeling something was wrong and ordered them to return, Frey tells Art about this when he flies in.
3 is valid, the best mental gymnastics I can come up with is that maybe the Commander's attack relied on magic that got canceled out, and Urk is just using muscle power.
4. Queen is aiming for despair, the smile pasted on its face got wider when the mages had their magic blocked. So, it makes sense that it lets them hype themselves up, before unleashing another attack they hadn't seen before, and laughing at their reaction.
5. He's been struggling with the idea that he's just a simp from the first chapter, a dense MC in a romcom, and that he has freewill like Urk said. So here he just puts all that aside, told the fmc that she's the most important to him, wants her to domme him, and asked her to command him to his death.