User blog comment:AYET/Strawhat Pirates Armada/@comment-6920514-20130506224229

Since Luffy is supposed to resemble Roger so much I'm sure we'll see this issue addressed at some point in the future like with Shiki asking Roger to join his massive armada. Roger had no interest in such things and Luffy would be the same. 1 ship, 1 crew. I imagine this alliance with Law won't last past defeating Kaido and they'll go their seperate ways.