I have looked at the stats of the ZSU and I look at that as anti helicopter with some missile defense. I look at the TDS and SAM as anti-missile with some anti chopper. So to protect a city or 4 (depending on the physical grouping) I have MPLS on top of mountains, 1 TDS/1 ZSU in a city. I have repelled invasions from 5 countries and then counterattacked them to defeat them. TDS shuts down cruise missile attacks.

Sometimes, "melee anti-missile defense" just doesn't work, for a reason i don't understand.

Hello gents,
As far as game mechanics go, it is impossible for a missile to both deal damage and be destroyed at the same time. Due to random factors in combat system, it is possible that the missile happened NOT to be damaged, as conducting just one "test" is not enough. We will look into the issue nonetheless and come back to you.

To add a little more information, i'll say that this is independant of if the unit has used or not its AA round.
I witnessed such a "close kill" of missile from a SAM that had already used its AA. Funnily enough, the TDS next to him took another missile and died.

Now, before this is fixed, i would like to say that maybe, it shouldn't be fixed and should be treated as a potential feature. I mean, Random factor may spice a bit the game, total determinism is a bit lame. However, if sometimes "defenses fail", this implies a net loss of efficiency for the concerned unit, and calls for a "stat buff". This way, sometimes the operator of the Otomatic may commit an human mistake, and let the tomahawk hit its target, and sometimes, he could be god-inspired and not let pass anything