I'm assuming you mean current Authority.
Probably the Authority, but Surfer complicates things.
Potentially, the Doctor is more powerful than Doc Strange (yes, you heard me right). And Jenny is freaking uber too.
Hulk and Namor are basically non factors. Angie, Jack, Apollo, etc. could take either of them. Hell, even MN'er could annoy them for a while while the big boys decide the fight.
Surfer could drain Apollo easily, but the Doctor could turn Hulk/Namor into trees too. I'm assuming both parties would have some shielding from the magic-types to prevent such quick disasters.
Then it comes down to whether or not you think Jenny/Doctor could take out Strange/Surfer. But the Authority has the advantage with the rest of the teams (the non-ubers) so they might help some too.
I could see Swift/MN'er annoying Hulk and Namor while Jack, Angie, and Apollo help Big D and Jenny take out the Defenders' big 2.
So the numbers advantage wins. If it were a straight 4-v-4, I'd probably give it to the Denfenders.
But Authority 6/10.
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{edit} I read DC's assessment. True for the most part, but he's not including Jenny.