I would think Hal potentially could overpower Zod, if given the time and incentive, and more crucially the opportunity. But... Recall that issue of Wonder Woman where Maxwell Lord has sent a killer Superman against the Amazon and she is fighting for her life - "..He has so many Powers..."
A key point to bear in mind is that a Kryptonian or Daxamite isn't any conventional, stationary, foe. Hal or Kyle can provenly deal with a Mongul, or even a Cyborg-Superman, albeit with degrees of difficulty, but neither of those use flight or speed, whereas General Zod and Faora do. And more besides. We've seen Hal capable of taking severe hits from Mongul or Parallax, but If a Green Lantern is being hit by full-on super-speed the fight is going to be over before they can even think about what is hitting them... and after all a powered Kryptonian/Daxamite is typically cited as being the most powerful geneology out there in the universe - near unstoppable. And there is a consistent record over the years to support the sight of Hal and Kyle being lucky to be left alive after two ruthless Supermen had their sport... they are simply overwhelming opponents to have to face without any plan or fore-warning.
Below is an example from Robert Venditti's ex writing partner Van Jensen, showing the Durlan spy Verrat Din adapting form to a Daxamite's biology to face the Green Lantern Corps, and she wasn't even at full power!
Superman has usually been shown able to overpower pretty much any single GL, save for the Daxiamite one with his ring, so guess this is just another example of that!
And Zod seems to be shown as what Superman could always be able to do, its just that he is not ruthless...