Come on, fried did not even vaguely hold his ground against mira.... He ended up basically screaming in desperation at the sheer volume of magic power mira has. Fried is powerful but I don't see what exactly would put him over gajeel. Would he put up a fight against gajeel? Definitely, be stronger? I doubt it... If anything I would argue that fried has at most shown the level natsu or gajeel had shown before the timeskip (no clue on how powerful he would be now though).
He did do fairly well in the physical battle after he turned himself into a demon as well. But that speaks more to the fact that Mirajane spent a year as an S-Class wizard, stopped improving when she was 17, and doesn't quite measure up to Laxus, Erza, and Mystogan. She's catching back up, but being too low on magic to fight effectively after using Satan Soul against Elfman only to be KOed by a sucker punch speaks volumes about how far behind the other S-Class wizards she was.
He managed to land several blows before being overwhelmed, better than being helplessly one-shotted. Then what is it that you see that would put Gajeel above him ? What did Gajeel show before the timeskip ? Shown the same level as Natsu, true, since Natsu is the main character. But what did Gajeel do to get lumped with those two ? His helpless defeat against Natsu in full-power ? His struggle to draw against a cat ? A cat who was worthless against the Seven Kins ?
Pantherlily was worthless against the Seven Kin? He lasted as long against Azuma as Mirajane did. He did that as a swordsman without a sword. When he was defeated, he was defeated by Azuma's Tower Burst, which appears to be Azuma's best attack out of his own resources. Mirajane went down to some random time bomb Azuma set. Furthermore, calling Gajeel's battle with Pantherlily a "struggle to draw" is rather a stretch. Gajeel handily shattered Pantherlily's sword, then doesn't seem to have bothered to use any powerful techniques afterward. Even so he fought without any real problems until the time came to deal with the whole one floating island about to smash into another.
He won, you say ? He didn't look like the one standing to me. If Erza didn't arrive there, the goat dude could've killed him 10 times over. And even if he won, doesn't change that he was left in a miserable state against two dudes who acknowledged themselves as far inferior to the Seven Kins.
He was still counted in series as having won. That the dog member was not in shape to get up and continue things. As for the two of them being inferior to the Seven Kin, people seem to have drawn the wrong conclusion from that. It doesn't mean that they're really, really weak. Other than Erza, all the members of Fairy Tail that fought the Seven Kin were "far inferior" to the kin other then Meredy. So Yomazu and Kawazu are probably around the same level as Natsu, Gajeel, Gray, Elfman, etc. And Gajeel beat both of them.
People, just because it came in a comedic manner, doesn't mean it's a joke. Everyone was shocked at how easily she defeated him, and then Laxus came in to laugh at how weak Natsu is for losing to Erza like that. Do you think if it was meant as a joke then they would take it that seriously ?
It is a joke. It's a running joke in the series that every time Natsu is running around yelling "Fight me!" at a stronger member he gets one shot. It's utterly meaningless as evidenced by the Festival Arc. Laxus defeats Natsu in one casual blow at the start of the arc. Natsu dusts himself off unharmed a short while later, goes on to fight Laxus again. This time while Laxus is taking it casual, Natsu is an even match for him. When Laxus gets serious and enraged and stops holding back, he still can't put Natsu down for the count with one hit. Even when Laxus pulls out his trump cards and catches a surprised Natsu with a Lightning Dragon's Roar, it's not enough to KO him at all, when the casual blow at the bar had Natsu out for a few minutes. Erza casually defeating Natsu in one hit falls into the same category as that one casual blow Laxus just couldn't replicate when it was time for an actual battle.