I'm not sure how you classify a western RPG versus a JRPG, but the thing that stands out in my mind is that those games are full of elements that commonly define each of them, and that makes sense, given the lineage of each branch of "RPG". Western RPGs stick closer to tabletop stuff, as that's what developed in the PC scene. JRPGs started out that way, but whisper-down-the-lane and iteration on what they'd already made tended to make different characteristics more prominent. So Miyazaki was likely more familiar with JRPGs, but he's also said that he was inspired by the difficulty in understanding English D&D, which is why Souls games feel so much like both western RPGs and JRPGs.