Guys, thank you for your valuable insights and the edits you’ve made!
I actually didn’t specify the cultural context this “tribal hero” belongs to, but after all it’s not much the outfit I was interested in, but rather a stylistic solution which is both realistic in the proportions and stylised and plain in forms and colours.
Anyways, I’ve tried to put your suggestions to good use and this is the result. The only problem yet to be solved is the chest, which I’m struggling to depict without exceeding with details. I even thought about leaving it as it is.
As far as proportions are concerned, I’m more inclined to portray him as a romantic hero such as Ulysses rather than a brutal one like Conan or Kratos. I mean, preferably athletic and smart more than brawny.
Finally, then, I’ve decided to remove the ponytail as it seemed to remind too much of Khal Drogo.