as we know, Sora knight of the sea is a WE times comic that was mentioned way back at the beginning of WCI. As many mentioned at the time, the seemingly insignificant comic was likely foreshadowing. But foreshadowing of what? Well in addition to revealing the designs of Ichiji and Niji(who at that time were unknown), I think the comic also foreshadows the SSG.
While many presume the SSG is a new group, nothing suggests that to be the case. The SSG could have always existed in some form, however only recently, under the leadership of akainu, become strong enough to rival the power of the shichibukai. But it really does make sense. While Judge's wife was also named Sora, Vito says that the comic was based off marine exploits. Meaning that Sora(Sanji's mom) was either a marine or the character of Sora was based on multiple people.
In either case, there is some marine who Sora parallels to. While some have said this to be sengoku, due to Sora having a sea gull, does it really make sense for Sengoku to seemingly use tech based power ups? So who is the marine that Sora is based off?
I think, given how he is shown using high tech weapons and fights alongside a transforming robot, its pretty clear that he was based off the marines of SSG with the robot likely being a very early version of the pacifista.