The strike ability is good but IMO the no retaliation and high init make these units great, expecially early game if you're trying to minimise losses. Their high initiative means they always get first and last turn so you just need to wait, then strike at the end of the turn and retreat to safety at the start of the next turn.
An added bonus is everytime they poison an enemy, it counts towards the Alchemy Medal which in turn boosts the effect of their poison!
