User blog comment:IamJakuhoRaikoben/Chapter 466: Assassination, Review./@comment-1359322-20151216073212/@comment-25111584-20151216083130

You're mixing up power and technique. FDKM Natsu > Jellal in power. But Jellal all the way for techniques.

Take a look at Acnologia vs. Igneel. It's obvious that the latter is way more powerful. But Acnologia has technique. He was able to devastatingly weaken Igneel by extracting his soul with DSM.

We were also told in Tartaros arc that destroying Zeref is not simply about power. It actually invloves quite a bit of theoretical knowledge.