"Sal Buscema drew [the Secret Wars II cover] originally, but Shooter found fault with his version and called me in to do a "better one". I took one look at Sal's and drew exactly the same thing, just in my own style."
Later, Fantagraphics used the rejected illustration for the Amazing Heroes cover, which was published one month before Secret Wars II #1."
These are the original pencils taken from Amazing Heroes #66. As you can see a whole lot of characters were cropped out of the background, including Dazzler in her old school uniform, Legion, and Magik. And Magneto and Rogue were added in to the final cover below.
Here's the original cover: