To keep you busy reading (until some real answer comes here) :

A reddit post about a similar question : ( u/Iphikrates )

https://www.reddit.com/r/AskHistorians/comments/6rvusy/is_the_military_worship_of_the_spartans_really/

An historian's blog about the depiction of Sparta in popular media (think the '300' movie) :

https://acoup.blog/2019/08/16/collections-this-isnt-sparta-part-i-spartan-school/

Edit : added credit for reddit answer.