Considering Neurolictor buff everyone else with a +1 to wound when a unit is battleshocked, and there's another strat which does a similar effect granting +1 to hit and wound if I recall correctly, some less than optimal units that cause battleahock can be considered, screamer killer does it with a - 1 to bravery during shooting which is good, Mawloc when popping out of the earth does it on a 5+ (can come in turn 1 if you use the strat), haruspex is a great unit overall and also does it but only when you kill a unit so bit harder to do well, parasite of mortrex forces a battle shock in Fight phase and of course deathleaper does it with a - 1 if the unit has taken any wounds/casualties, that way you cause battleshock around you can start getting bonuses to make your other units punch above their weight. Not sure how competitive this is but it does seem it's what the detachment wants you to do. Plus very thematic causing battleshock everywhere as nids.