Spartans were good at war
Spartans loved smashing ass
Therefore smash ass to be good at war
Spartans were good at war
Spartans loved smashing ass
Therefore smash ass to be good at war
Spartans were kind of shit at war.
Now, the Theban Sacred Band? THEY were good at war and smashing ass
Sure, but if the Spartans were shit at war they wouldn’t have had the century and a half of being undefeated in decisive battle that would form the Peloponnesian League from their conquered subjects in the first place.
The League that then led the war against Xerxes, and eventually conquered Athens, Thebes, and Corinth, a hegemony that would only be broken by the man whose tactics would teach Phillip II and his son what’s-his-name how to conquer most of the ancient world.
That simply is not being shit at war, even if a critical analysis shows the Spartans did not perform notably better 1:1 than anyone else without trading on their reputation.