Punk/Lesnar is literally the only well built match on the SummerSlam card right now.
Another great segment, and that's exactly how Punk should've gotten the upper hand on Lesnar: with savvy and weapons. And unlike pretty much every other big match WWE does, they've left a lot for the match to accomplish as well. We've seen Punk beat him WITH weapons, but what happens when it's really man-on-man, fist-to-fist.
If I were to guess, I'd say that Punk, Heyman, and even Lesnar might have put this together themselves.