So I watched this fight again, and I have some things to add. Although my opinion on the fight remains the same, I just want to drop an observation. From what I've seen, Piccolo has a good shot of winning this.
When Broli first goes LSSJ, most of his early attacks are aimed at Gohan. Each time, Goku stepps in to save his son. This happens back to back to back to back. A total of four times in a row, Gohan is protected from Broli.
Broli's first blast as an LSSJ goes directly at Gohan. Goku pushes his son out of the way. Broli charges them, Goku grabs Gohan and turns his back to it and acts like a shield. While being chased by Broli, Goku drags Gohan by the arm, flying out of reach from the raining spam of ki blasts. They are both in base form through out this ordeal.
This is a far cry from the Goku who refused to allow anyone to step in for Gohan during the Cell Games. Also, I don't ever recall Goku going through such a continuous effort to keep Gohan out of harms way. Maybe once or twice, but not a full on getaway for an extended period of time.
Either Broli is enormously above Cell or this Gohan is nowhere near his Cell Games self. In fact, Gohan is the only Z Fighter that needed constant saving in M8. If you count Piccolo stepping in, Gohan is rescued from at least five different attacks. In my humble opinion, even SSJ Gohan is clearly the weakest of the group who challenged Roshi.