No look out, but the normal shooting hits are distributed evenly by the controlling playing.
If I stick the herald on palanquin into a unit of 4 beasts, and the wood elf player pours fire into them (scoring 21 hits for example), each beast takes 4 hits, the Herald takes 4 hits, and then I choose who takes the 21st hit (I choose the beast). The elf player then rolls to wound 17 times on the unit, and 4 times on the herald.
If the same unit goes up against empire, he fires his cannon into the herald, and the herald takes the hit.
The other option, stick him near a unit of Blood Crushers.
21 hits scored on the herald, and on a 4+ those hits are transfered to the Blood crushers. Since S3 save -1 is actually a threat to blood crushers (underpowered), that's not a brilliant idea.
On the other hand, when facing Empire, getting a 4+ look out vs the cannon his is pretty awesome.
So what's the morale of the story?
In a take all comers list, it isn't a horrible idea to run blood crushers.
A lot of armies don't get both cannons and effective normal shooting (O&G, Ogres and Daemons all have effective warmachines and ineffective
BS based shooting). Often empire shows up without
BS based shooting. That only leaves dwarves and tombkings where you need to worry about both warmachines and
BS based shooting.
-Matt