From the flashbacks, we see how Arlong dressed 8 years ago, when he was a bit younger before growing his crew to the empire we see today. His choices remind me of an edgy teenager in a fedora and trenchcoat, trying to seem much cooler than they think they really are. In a certain sense, it does appear as a somewhat more “professional” outfit than the beach-casual clothing he wears in the present day, but it also seems like an attempt to be intimidating or convey a tough-guy persona. The clothing represents a desire to be taken seriously, sharply contrasted with his more comfortable clothing choices after he established Arlong Park with steady income & a terrifying reputation.
Arlong’s language about Nami only living up to her true potential if she serves his goals indicates much about his worldview, showing that he believes his goals & his success are truly the only important things in the world to such an extent that even other people should only find meaning & purpose in their own lives by assisting him in conquering the East Blue. He then projects that same mentality onto Luffy, assuming that the Straw Hats only seek to “rescue” Nami so that they may “own” & “use” her in the same manner. Fascists only see fascism wherever they look.
Luffy destroying the sea charts does more than simply hinder Arlong’s pursuit of domination. By erasing the years of work Nami was forced to complete, he has also stolen her labour back from Arlong, even if it is still now useless to everyone. This is mental & emotional vindication for Nami, allowing her the peace of mind that the actions she took which helped Arlong, even under duress, will no longer serve the fish people’s goals, which evokes closure on that period of her life without worry about what harm they will continue to invoke using her skills.
While Luffy’s immaturity & lackadaisical attitude are often shown to be beneficial, we are given an example of how his lack of focus & determination hinders his ability, or at least how it is determined by his state of mind outside of his own agency. The battle between him & Arlong is fairly steady & evenly matched for quite some time with both characters seeming equally matched until they enter the map room. Upon discovering the facts of history, and realizing the depth of Nami’s mistreatment over the better part of a decade, something snaps within Luffy, allowing him to vanquish Arlong & crush the entire building with relative ease. Had he full self-control & mastery over himself, he could lead with this level of combat prowess, ending the fight much sooner.
The Marines are all bark & no bite, utilizing their reputation & image as keen soldiers to impose fear & control over their subjects, taking whatever they want with impunity. However, we see Zoro, still suffering from his critical wounds, easily dispatch the entire group within seconds. It has been made clear that some Marines are better than others, and a few dozen episodes ago, they were able to capture & imprison Zoro, but many are indeed just living fat on the general conception of what the other ones are capable of. In fact, most real world governments also rely on these same tactics of propaganda to convince their populations to fall in line & obey unjust laws under threat of punishment, when it is rather obvious that the oppressed & working classes could overthrow their authoritarian dictators were they to band together and resist.
Last note, I have absolutely zero comment on these snail radio devices, like what the fuck even is that, why is that a thing, how does it work, holy shit, I have no idea what I just saw.