"The poor men eat the soup."
Translation:Les hommes pauvres mangent la soupe.
Subjective/figurative nouns go before the noun. Objective/literal nouns go after.
A man has or does not have money. It is an objective description. Pauvre meaning without money goes after.
Whether a man is truly sad is relative and therefore subjective. Pauvre as miserable, sad etc. goes before the noun.
The B.A.G.S. convention is a shortcut to determine adjective position because adjectives that describe Beauty, Age, Goodness (or badness), Size are usually relative or subjective/figurative and thus go before the noun.
A man who is bad in your opinion is un mauvais homme.
A man who is objectively bad, perhaps he has been convicted for such, is un homme mauvais.
All adjectives are subjective by nature so except when you are being tested for accuracy, no one will stop you and say that you are all wrong in any particular instance. On the other hand if you want to say what you intend it is good to notice the subtleties.