I'm really wondering how Eminem and Royce distributed the writing here. This is the one instance where I'm not entirely sure because Eminem and Royce had the same rhyming philosophies.
I would think the "we hit the trees/Vietnamese people" stuff was Eminem's, but what about Royce coming in with, "he's insane" after Eminem says, "cold enough to make the seasons change into freezing rain?" To me, that sounds like something Eminem would have written for him, but did he?
And then at the end, Royce adds a couple new lines after repeating the first two from Eminem's extended hook.
It's not like it is with Dr. Dre, where you can be sure the entire thing was crafted by Eminem, so any woven back-and-forth stuff is irrelevant. In this instance, it's like you have Michael Jordan in the studio with Kobe Bryant. "Wait, who did that move? Seems like something Jordanem would do, but Kobe da Bryant is dope enough to where one can't be entirely sure."