I see it mainly in Fantasy Books.

One Brother is the good one, he is manly, strong, don’t care about riches, and have a good heart. He will be the protagonist or the protagonist friend.

The other one is the Bad Brother, he have a more weak body, have femine traits, always using fancy clothes and jewels, is less loved by others, and he is jealous. He will be the antagonist.

In a arc of >!Ranger!< this trope is reverse, which was a breath of air.