Who writes most of Bruce Dickinson's solo stuff? Is it Roy Z and Bruce just writes lyrics and sings over it? Or does Bruce also have his own riff ideas and such? As much as I adore all of Bruce's solo work, I'm not a fan of the ego behind artists having a "solo project" where they write less than half of the material.
According to Bruce's book Roy writes most of music and arrangements, while Bruce writes vocal melodies and Lyrics. At least AOB was written like that. I would assume same with H's contributions.