Bendo was supposed to kick Edgar all night, he managed it for the first round and despite being successful, Frankies pressure and boxing forced him away from that strategy. Bendo said it himself.
Diaz is the perfect fighter to exploit that better than Edgar did.
While Diaz's boxing may cause a problem for Henderson, keep in mind one thing: Diaz is much much slower than Edgar, in terms of movement in the cage.
Edgar bounces around like a rabbit on crack most of the times. His constant movement is what made it difficult for Henderson to catch him time and time again with the leg kicks.
Diaz with his "in your face style", coming forward to you, is much more likely to be on the receiving end of Henderson's leg kicks. And if Bendo lands a big ammount of leg kicks he will slow Diaz down even more.
Secondly, Diaz's wrestling problems. He has shown it time and time again. The first time in a long time i haven't seen him have problems was against Miller. But Miller isn't a high caliber wrestler like Henderson imo. Proof of that is their fight, where Henderson controlled Miller for most of the fight on the ground and inflicted big damage with heavy GnP.
Diaz may be more dangerous from the bottom, in terms of submission attempts, but Hendo is no slouch when it comes to submission defense, and he proved it time and time again: against Cerrone, Miller, Boceck or Pettis.
Diaz's history against bigger-stronger wrestlers - like Rory, Guida, Maynard or Kim, makes me believe he won't be able to fend of Henderson's wrestling attacks and he could find himself on his back looking for sweeps or sub attepts, while trying to avoid GnP.
In conclusion i believe the key to this fight is Henderson's strategy: i think he might go for a mix betweeen Condit's strategy against Nick and Rory MacDonald's strategy against Nate. Leg kicks + point fighting and then trying to take the fight to the ground, scoring with GnP.
My money will be on Henderson, for a clear UD: 49-46 or 50-45.
With respect, Diaz's boxing, while very effective, is miles away from Edgar's boxing in terms of styles and how they're implemented in the octagon.
In addition, IMO Diaz is slower than Edgar.
Much much slower.
And that will make him a much easier target than Edgar ever was.