About the only time I have trouble with overload is virtually every time I do a scenario involving the Soviets
Tho it occasionally comes up on smaller scenarios where there is extensive air support.
As an example if you did something similar to the "We Were Soldiers"
https://en.wikipedia.org/wiki/We_Were_Soldiers and tried to cover the while battle you'd run into problems with air support because unlike artillery/mortars they're a one use item so you'd need to have a ton and they count as "artillery".