Much simpler, IMHO single letter = sound letter + z = "hissing" version of the sound letter + accent = soft version of the hissing sound letter + i = same p

Much simpler, IMHO single letter = sound letter + z = "hissing" version of the sound letter + accent = soft version of the hissing sound letter + i = same previous item, but caused by "i" rz = legacy, czechs still pronounce it as a different letter This is how I understand it as Ukrainian