It is subtle things like this which make this the best manga ever. No two characters are the same. Every character has their own personality, their own goals and motivations, their own strengths and weaknesses. They're all fleshed out to such a ridiculous extent that 99% of other manga just look utterly flat and vapid by comparison.
Heck, even the fact that the 7th Division soldiers mostly wear the same uniform but their faces are unique enough that the only two it is even possible to mix up are identical twins is so very perfect. Too many manga have characters that are basically copypaste if you remove their hairstyle.