> Sparta at its peak was 10-20 times smaller than Athens.
No, it wasn't. It had a broadly similar population; it's just that most of that population were slaves. And they did have slave auxiliaries, so it wasn't necessarily a manpower issue.
It is about 10 times if you count slaves, 20 if you don't.
They had conquered other territories which they used as auxiliaries, yes, but those were just normal Greek troops and wasn't anything special or unique to Sparta. And the reason small Sparta could conquer them in the first place was the strong army they had. Not strong as in super human, but strong as in numerous well trained soldiers. Anyone who made their kids practice warfare got soldiers to that level.
No, it wasn't. It had a broadly similar population; it's just that most of that population were slaves. And they did have slave auxiliaries, so it wasn't necessarily a manpower issue.