If anything, this weakens the argument by suggesting that the little documentation concerning Caligula’s cruelty isn’t particularly significant. If there’s less documentation overall from his time, that could explain why there’s not much documentation of his cruelty.

This doesn’t help suggest that Caligula wasn’t cruel. We don’t know whether Caligula was regarded favorably or unfavorably.

This strengthens by suggesting that the descriptions written by Caligula’s enemies concerning Caligula’s outrageous acts may have been copied from earlier writings about other rulers. It provides evidence suggesting that those accounts about Caligula may not be reliable.

How Caligula’s reported cruelty ranks compared to others doesn’t affect whether Caligula was in fact as cruel as reported.

This suggests that there have been modern tyrants who did things that were more cruel than what was attributed to Caligula. But this doesn’t suggest that Caligula wasn’t cruel. He might not have been as cruel as others, but this doesn’t mean his cruelty has been exaggerated.