Billy noticed that some of Alexander's students were hurt in the shoulders and wrist. It was evident that Alexander showed them the improvement in that skill, and they tried to copy. However, their bodies weren't strong enough to endure the strain. They probably tried that version without even knowing the original…
In any case, while Alexander was making his body get used to that kind of skill, his students headed toward the dungeon using the same schedule Billy used with Lily. Although they were all melee fighters, Billy assumed that they would last longer than the archers in the beginning, and while they did that, it was barely noticeable. In the end, Lily's students improved from one hour to five, but they failed in fulfilling her expectations. As for Alexander's, they managed to stay for one hour and five minutes.
"Do you want to spar, Billy?" Alexander asked while he saw Billy almost falling asleep near the entrance of the dungeon.