(FYI: I'm posting a new thread because the other is degrading into unrelated and unhelpful personal attacks.)
If avians come back they need a niche. Attacking fast isn't enough, gnomes attack fast too. Just being an attacker isnt enough. I suggest, making them into fast hitters, along the historical lines of Vikings or the Huns. They were mighty warriors who could mass armies, but their real power, the terror they instilled came from their raidings and plunderings. That can be their niche.
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-50% attack time for plunders, learns, conquest and massacres
Double thievery effectiveness for intel and robberies
+1 ospec and dspec
+75% pop growth
+25% combat losses
can't use stables
7/3 elite $800
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Now, they've still got a lackluster Econ, and in a landswapping war they'd be hard-put against other attackers. Outide of war, they'll be able to plunder and steal for good growth. Before war they'll get a few non-land waves in before switching to ultra fast conqs. They won't be able to put up the kinds of numbers other races do, and in war they won't be able to move the meter remarkably, but with fast conqs they'll do just fine. The thievery just rounds them out, gnomes can still run roughshod over them with damaging ops, but the avians will be the best robbers around, good at getting surveys and soms, and tough to get intel off of.
Quick note: depending on questions of power, the attack time bonus and combat losses can both be moved up or down 10% depending on views.
Additionally, a hidden weakness is that they won't take honor the way other races can.