Mark Ronson's best music is created with Amy Winehouse, Adele and Bruno. 3 artists as heavily involved in their music as Gaga is.
You can make the same argument about Mark not being the mastermind.
Furthermore RedOne choses to produce generic music, in generally he tries to appeal to radio (and not USA radio) he has always worked with latin artists since before Gaga...
y'it's not like he tries really hard to create some different music or acclaimed music... he doesn't even follow US radio, he usually works with PitBull, Enrique and the likes
And most of his songs are hits outside the USA and so will be his new song. Also I would never want Gaga to release something like his new song, and I know they won't.