By every rule of drama and writing that I know, the "villians" should of won that fight. This was basically the first time we ever saw Sting and Rogue do any fighting. They were built up. They killed DRAGONS man. And then Natsu just mops the floor with them, after both he and Gajeel take on their DRAGONFORCE mode attacks without breaking a sweat.

The least they could of done is have Natsu and Gajeel atleast look hurt, and have Natsu collapse after using so much energy to beat the two of them. Make it atleast look like he had to exert effort to beat them.