I think as long as Cung Le uses his range to get in a few solid leg kicks, he'll win. I think that'll take the wind out of Renzo's sails. It's hard to trip someone when you can only stand on one leg.
Once Renzo's feeling the swelling building up in his thighs, I think Cung has this fight.
I really personally hate the way that Gracie fights. I can always appreciate some good Jiu-jitsu but Renzo is not active on the ground.
It always looks like he doesn't even go for a finish. Appearing more so as if he's looking to equilize his opponents activity and is comfortable to lay on top and squeek out a victory in a side mount.
With that said, his take downs are always fluent, and I see him dry humping a victory out of Cung. And holding the belt until he encounters a real BJJ fighter. Or even a fast striker that'll KO him when he shoots.