User blog comment:AYET/The worth of the Shichibukai to the Marines/@comment-5962458-20130529072238/@comment-3425840-20130530014432

Well Whitebeard's ally (reputed NW pirates) had to struggle and team up to beat pacifistas. I agree that top level NW captains would wreck them but not all pirates. And marines are not only after NW pirates, pacifistas are great to deal with rookies in paradise or other blues.

As for Usopp, i think the only way he can take down a pacifista alone is by the use of ultra heavy plot armor :P