I see the confusion now. It's the way you interpreted the sound keyed by 'p(h)wī The intent was a hard p in front of (h)wī - here is audio for the (h)wī Isn't that what you had in mind?
I would pronounce it as "pwy", but as already stated would not want to make a commitment without being 100% certain. I see no reason for the h and dont see it as "fwy" or any other way that requires the h.