I was more thinking using AA as an overpriced infantry.
They (particularly Mobile SAMs) are stunningly (unrealistically) robust as melee units. Compare Mobile SAM's 65 combat strength with Infantry (70 CS) and the Mobile SAM's Atomic Era compadres - Tank (70 CS), Marines (65 CS), Paratroopers (65 CS). Even the AA units are surprisingly strong (50 CS), compared to their same-era counterparts - Foreign Legion (42 CS) and GW Infantry (50 CS) -- although they are stomped by regular Infantry (70 CS).
They really should have made AA and Mobile SAM's incapable of attacking (with their combat strength only used for defense).