Meme

I don't really understand what you mean by below average military record, below average compared to what?

The speeches made by members of the other city states in the "History of the Peloponnesian War" show that the other Greeks considered the Spartans a cut above everyone else with many Athenian thinking fighting on land should be avoided unless absolutely necessary.

The meme is probably right insofar as Sparta has more cultural relevance than they deserve, but is wrong in that it treats history like comparing which superhero was the strongest.