User blog comment:Apoelpaoole/X-Bracelet on Mihawk-Doflamingo-Blueno/@comment-4679046-20130317072651/@comment-5387880-20130317101957

In terms of skills: they don't need to have similar abilities in order for them to be in the same group(strawhats for example). They are in a whole different level as well, it doens't mean that everybody needs to have raw strenght, Blueno could be a spy with his DF, while the other fighters..

And yes it could be that just Oda drew them without a reason even if I doubt it...