Discrepancy in lore (spoilers)

[Jandor]

It does bug me a bit yeah that they never really seem to use their theoretical air superiority.

We even went and dealt with the airship issue over in Doma, and they were shown to be better able to deal with aerial enemies than we are, but in Eorzea everyone just went nah it'll be fine and then we won anyway.

More fool you I guess, Garlemald, imagine thinking virtually uncontested aerial superiority would give you the edge. That sort of thing just doesn't cut it when you're facing a land army that can throw fireballs up to a whopping 25 yalms!

[Brightamethyst]

More fool you I guess, Garlemald, imagine thinking virtually uncontested aerial superiority would give you the edge. That sort of thing just doesn't cut it when you're facing a land army that can throw fireballs up to a whopping 25 yalms!

Garlemald's last aerial invasion of Eorzea ended with the fleet being massacred by dragons and Midgardsormr personally destroying the flagship. Gaius himself said the cost was too high.

[Jandor]

Garlemald's last aerial invasion of Eorzea ended with the fleet being massacred by dragons and Midgardsormr personally destroying the flagship. Gaius himself said the cost was too high.

An outside force of magic flying space aliens fighting the Empire to a standstill at the cost of their own millennia old leaders body is probably the worst example you could come up with if you wanted to show that Alliance can successfully deal with airships on its own.

A: The alliance didn't do it.
B: It didn't push the Garleans back beyond where they started.
C: The cost was arguably just as high, if not higher, for the dragons.

Just to clarify, my criticism isn't that the Alliance can take out airships, it's that we're never shown, or even told, how we're doing it.
Air superiority is important, very important, and I want to know how we're handling that aspect of the war. I can fill in the gaps myself if I have to and come up with plausible enough explanations; dragonkiller support, dragoon boarding parties, rogues sabotaging them in dock, etc. but I consider it important enough that the story just kinda glossing over it annoys me.

[Vyrerus]

An outside force of magic flying space aliens fighting the Empire to a standstill at the cost of their own millennia old leaders body is probably the worst example

Within the context of the game world it isn't. The Garleans don't know that dragons are aliens, for one thing. For another, to them Eorzea is a frontier. Not only do they struggle to combat Primals without recent technological marvels, but the amount of resources they pooled into the Agrius was substantially high. They sent it in, fully expecting it to absolutely crush all opposition and raze Eorzea mostly to the ground. Instead, it's a scrap heap in the middle of a lake.

Also, aerial superiority doesn't mean as much in this world, as it does in ours. Case in point, flying Imperial dropships bombard you during the last segment of Keeper of the Lake. Not only are these bombardments non-lethal, we can anticipate where they land more precisely than the Garleans aiming them. Without a rapid fire bombardment, their normal air units can't even touch us.

Add to this, they tried the same trick twice. They built yet another dreadnaught, being a FF Empire, they are addicted to constructing them. It has been unable to leave Azys Lla for at least 15 months by my count from battle damage sustained from fighting ONE Primal.

So Garlean Dreadnaughts are O and 2 vs. Filthy Savage Magicks/Filthy Frontier Dragons. They're about to be O and 3.

To address your points directly:

A: Doesn't matter. Cost the Empire so much that they won't willingly commit that kind of force to Eorzea ever again, until the events of Stormblood.
B. It got rid of the mainstay in their military force, allowing the Alliance to engage them on somewhat even terms until Bahamut happened.
C. That's the Dragons' cost to bear, because they acted in accordance with the pact between Middy and Hydaelyn.

[Jandor]

snip.

Dragons and primals are the reason the Empire hasn't tried to push into Eorzea again, but given we're not using either of those in our armies they provide literally zero explanation for how we're forcing them back.

Dragons didn't help us at Ala Mhigo, we didn't have a primal backing us up in Ghimlyt Dark. Eorzean forces defeated Garlean airpower on their own but we're never told how.

[Vyrerus]

Dragons and primals are the reason the Empire hasn't tried to push into Eorzea again, but given we're not using either of those in our armies they provide literally zero explanation for how we're beating them now.

Dragons didn't help us at Ala Mhigo, we didn't have a primal backing us up in Ghimlyt Dark. Eorzean forces defeated Garlean airships on their own with zero in-game explanation how.

Our powers are substantial enough that we can, and we have dedicated mages and artillery for those occasions.

Shouldn't need a lot of explanation when there's literally cutscenes of the Xaela's flying on birds and down airships with axes and magic.

A cutscene of Hien riding a Yol cutting a sky armor out of the sky with one stroke of his katana.

We also have sidequests in Stormblood where the alliance takes Magitek and trains soldiers to use it.

[Jandor]

Our powers are substantial enough that we can, and we have dedicated mages and artillery for those occasions.

Shouldn't need a lot of explanation when there's literally cutscenes of the Xaela's flying on birds and down airships with axes and magic.

A cutscene of Hien riding a Yol cutting a sky armor out of the sky with one stroke of his katana.

Powerful groups of dedicated anti-air mages backed by artillery? That sounds cool, would have been nice to ever see that.

The Xaela tribes aren't deployed in Eorzea, and they don't fight any airships. They fight a force that as far as we can see consists entirely of the much much smaller Juggernauts, those things aren't that much bigger than a Yol.

Funny you mention that Hien cutscene too, that would be the cutscene where Eorzea is yet again failing when up against Garlean air power, and yet again have to be bailed out by someone else?

Seriously, what sort of absolute morons don't expect to face aerial units when sieging a city held by a faction known for air power? What an absolute clown show of a military campaign.