[quote=@Cyclone]
[@Willy Vereb]

Tin and KalMea have a sort of supply truck/troop carrier that we were going to say was also designed to tow along those AA cannons. I might still keep the .88 inspired things, but anti-aircraft mounts on vehicles isn't a bad idea either.

But keep in mind that most people have airships rather than little planes. I'm thinking specialized units that shoot dumb rockets into the sky would be really helpful. A slow moving blimp-thing could be devastated by a few teams hiding under trees and shooting missiles up at its balloon.
[/quote]The problem is that the said blimps will also be rather high up in the skies. At least most types will.
So something like the good'ol Acht-Acht would be better fit for this purpose.
Missiles are technically light and easy to use but hardly reliable at such ranges. 
They make sense for aircraft because it saves weight for the same stopping power but they are kind of expensive and limited compared to artillery.
Also some airships are heavily armored here. Missiles won't have the same armor penetration as a cannon shell.
They have better range, cheaper ammo, more consistent fire rate and more versatile loadouts.
Bonus the fact you can use the AA cannon as a makeshift anti-tank artillery.
So I say the same as I previously did, stay with the cannons.
They do a far better job.