Do you think iconic songwriters ever secretly use uncredited songwriters to improve their work?

Take someone like Alex Turner. He's known for having a singular, idiosyncratic creative style. He's definitely a good songwriter but there was a certain perfect calculatedness to AM that really nailed the market they wanted to go into at the time.

Maybe he just read it correctly. But it was a pretty big leap to go from SIAS, which wasn't seen as a notable album amongst old and new fans, to AM which catapulted them to perpetual streaming royalty.

Similarly Green Day ended a slow decline in 2004 with the biggest album in the world which succeeded based on their sudden competency at writing in a style they hadn't approached at all on previous albums.

Is it just talent? Or do you think there is sometimes a songwriter or songwriters, outside the producer, at the band's disposal to suddenly help them hit an unusually hot streak? Considering that labels are also investing in the marketing for the album wouldn't it be in their favour to help their talent have something that will actually hit once they've spent all the money laying the marketing groundwork for them to have a hit?