Their outfits aren't nearly identical, they only look that way to us because we weren't there and don't know the details. It's no different than how classic cars all look close to the same but someone who was there can just tell you at first glance "that one's a <brand>, that one's the top trim, and so on".
Definitely but would you disagree that there is homogeneity to it that would be out of place in say a NYC street scene today? Look up pictures of Straw Hat Day. Just interesting to me given the wide world of fashion choices and styles that developed soon after.
