I feel like people forget how Maiden writes music nowadays. Adrian might have some developed demos and the rest has some ideas but they don't go with fully formed and previously written songs into the studio anymore. They book the studio, spend a couple of weeks there, Steve locks himself into a room and connects as many of his ideas into a 10+ minute song, while Bruce will sit with Adrian to work out a couple of songs. Afterwards Steve will work with each of the amigos. This is basically their process nowadays.