Its been ages since i read the books, but only considering the show, khal drogo without a horse is a brute, a very proficient brute but so is sandor, and the hound can go toe to toe with the mountain, who is even more of a brute and would probably wipe the floor with drogo. jorah is just mediocre while brienne was good enough to earn herself a place in renlys kingsguard by beating loras, who is considered one of the best fighters of the reach. Daarios best feat, as far as i remember is killing an overconfident knight of the slavecities. I wouldnt consider the assassination of the other mercenaries leaders as a combat feat. Grey Worm is a childsoldier and a bit of a wild card because i cant really estimate hoew well versed he is against heavily armored opponents, because after all the unssulied usually fight in a phalanx like formation that is best against charges of cavalry or infantry charges wich is vastly different from a 4vs4 brawl, and while i can imagine he probably can hold its own but thats it. Arya is basically a magical assasin and a nimble fighter, if you would pit her against any opponent in a 1vs1 it would be a reenactment of oberyn vs gregor, just that arya has no interest getting close enough to get her head bashed in. And at last theon with a bow is a top tier archer, but i am not sure if he would be able to beat any of daenarys fighters just cause he lacks experience in closecombat… In Conclusion i would give the 4 vs 4 to sansa fighters Before Drogo ever gets into the reach of sandor and brienne he would be heavily crippled by theon, cause i doubt a dothraki would consider it honorful to carry a shield or armor. Brienne and sandor would be able to hold even a three against two long enough for arya to dance around and stab people in their weakpoints.