A demon general is the direct subordinate of the demon lord; that's a well-known fact all around the world, not just the demon empire.
So, would they listen to someone who is asking them to go against the demon lord?
No, they won't—at least not until they want to betray the demon lord.
So Alex suggesting to Grum that he should ask for help from the generals was not actually a friendly suggestion; it was clear from the sly gleam in his eyes.
He was forcing Grum into a corner.
Grum now had only limited choices.
First, he could ask the generals—the beings he served under—for help, which would imply betrayal since he was in a way requesting the generals to go against the demon lord.
Second, he could simply try his luck in an attempt to eliminate Alex, maybe taking Alex down along with himself.
