Not a bad idea, done it myself. In my experience you usually have to support it for a number of reasons, Chiefly, anything that negates cover, which is a hefty amount at times. Hence why I camp a ravager nearby to keep an eye on them.
My friend deep striked, or Struck? a ironclad dread behind it once and unleashed either one or two heavy flamers on the poor sods and annihilated about half of them. (kabalites).
I think its worth saying yes they do work, in my experience, but you have to watch your opponent like a hawk, and keep it supported with a ravager floating about, I find having a haemy with a hex rifle helps a bunch (FnP)!.
Other than that don't bunch your kabalites together! space them out! Each and everyone of them! lol.