The skull mask is unique. I like the idea the Preds/Yautja attempt to adopt dedigns that blend into the times.
I was thinking the Preds probanly preferred fighting people prior to advanced human tech, because they were more mystical and wouodn't attempt to take Pred tech for military purposes; i.e. Preds don't need the wristnuke to destroy tech with more primitive peoples who view their tech as more supernatural rather than as alien and useful for developing tech.