yeah looking at the lowpoly, how straight the lines appear. i assume they built the lowpoly first, then used it to create the highpoly, not sure if it was actually sculpted or maybe just smoothed, baked and all surface detail is just done in a software like substance painter.
I'm a bit confused, OP-- have you tried to model it yet, or are you just talking to talk? There are a million valid ways to model this, and there's no telling how the original artist did it, unless they volunteer that information. All you can do is try, and see what works. There's a lot of good thoughts in this thread…