Whiddershins' comment has nothing to do with political correctness, but rather with actual historical correctness. The comment is polite, sincere, and provides a further source of information for those who seek it.
[1] The phrase is the analog of an idiom. It is shorthand for "hierarchy" and used as such. The parent is explaining its use.
[2] There are many tribal organizations. This cuts both ways. Provided there is a single one that was historically rank-hierachical, the data is not even a counterfactual.
[3] Provided [2] is ok, so is [1]. We know [2] is ok. Hence, the comment is logically ~gratuitous.
This is silly and trivial. Two reasons:
[1] The phrase is the analog of an idiom. It is shorthand for "hierarchy" and used as such. The parent is explaining its use.
[2] There are many tribal organizations. This cuts both ways. Provided there is a single one that was historically rank-hierachical, the data is not even a counterfactual.
[3] Provided [2] is ok, so is [1]. We know [2] is ok. Hence, the comment is logically ~gratuitous.
See, for example:
http://www.usingenglish.com/reference/idioms/too+many+chiefs...