I once saw some sentences like "My brother-in-law loves my brother" in screenshot of duolingo in social media. I think they are uncessarily confusing, especially for beginners.
Not so long ago that would have been considered a perfectly normal expression. Brotherly love?
It is normal (at least I should consider it normal), but not common (or should I consider it common?). We learn "apple, pear, banana" long before we learn "papaya, jujube, kiwi-fruit".
Like when programmers try to demonstrate features by using strings and symbols named the same...