Relative clause vs. の to "categorize" a noun

Question

According to my low level of Japanese, I know two ways to "categorize" a noun with an another noun + adjective:

• 髪が長い男の人が少しいる。
• 長い髪の男の人が少しいる。

Are these two sentences grammatically correct? Are they natural? What is the difference?

Answer 1

I think the following three sentences including your two are all grammatically correct and almost natural to native speakers of Japanese without any particular difference between them.

1. 髪が長い男の人が少しいる。(two が in a short sentence)
2. 長い髪の男の人が少しいる。(two の in a short sentence)
3. 髪の長い男の人が少しいる。(two の in a short sentence)

But as a writer I would like to avoid these sentences in my writing because of two particles in a short sentence, and the phrase of 人が少しいる sounds a little awkward. Then I have created this sentence with the same meaning.

4. 髪の長い男性が数人いる。