Hiya!
The thing that kept popping up in my head when giving the OP's post a "solid skimming over" was this: "So, why do all these other races seem like humans in funny suits?".
The majority of what "vibe" I got from each 'race' as a motivation was basically human. That's it. I didn't get any sense of "not a human" from them.
I think if some sort of "defend our land from invaders" campaign was to be had, and it wanted to focus on non-human creatures, well, wouldn't the first thing be to distinguish all the non-human creatures as...er... not human?
I don't know. Maybe it's just me. But when I hear "Aaracokra" I don't think "just a dude with wings". They would have VASTLY different ideas of what is right/wrong, good/evil, acceptable/unacceptable, desired/undesirable, etc. For example, I can easily see the Aaracokra having a huge sense of superiority over any non-flight-capable race to the point where there would be specific rules/laws that are granted to Aaracokra, then "other flight-capable" creatures, then "ground-limited" creatures being their 'slave/serf race'. Aaracokra (or Dragonborn, Tiefling, Genasai, etc) are not human, and reducing them to nothing more than just "humans in funny suits", to me, is missing a potentially HUGE opportunity for a campaign.
^_^
Paul L. Ming