I think the real tactics should be to never throw any aircraft at a lonely AAA.
A single ground unit is enough to destroy it.
When you can only reach that territory by air, and you want to destroy it, then just send 1 plane is enough. Unless, of course, the AAA roll “1”, then this AAA unit will survive.
Thanks for your question, it just showed me the OOB AAA unit have an additionnal complexity which doesn’t have any other regular ground combat unit.
This happen because the OOB AAA unit is an hybrid between the old classic capturable AA gun and a regular unit which can take hit.