User blog comment:FeaturedMe/Feat's Anime Review - Episode 151/@comment-5170433-20121006213921/@comment-121.54.8.130-20121007005121

don't say that Sting and Rogue are weak. Natsu is just stronger of course since Natsu is the main male protagonist. Sting and Rogue thinks they can beat Natsu and Gajeel because the two of them are among those frozen in time in Tenrou Island for 7 years.