What do you mean by damage from defensive systems? Do you mean damage on the kiting tank, damage from the knockback, damage from the adds? I can tell you that using the knockback may be dangerous and unreliable, and that the only one's taking consistent damage are the kiting tank and the last DD soakers.
I meant damage from the knock back, much like how i posted a log of the damage from 8 man. I asked for it because people were stating they were taking huge damage spikes from doing it, from unknown sources. I highly doubt that the damage would be more then 2k if that, and if people are taking additional damage it is from either; A) a bug or B) motor volley or C) single destruction. If it is a bug of some sort we will never know unless people document it, by sharing their logs.
As it stands you take less then 1k damage from the knock back when you dont have single destruction on you, in 8 man; making it a very viable and most likely prefer method to get the shields. I dont see anything that would cause a huge difference where it would become unfavorable to do in 16 man.