Originally Posted by
MattHoell
I would go for 4 units, it gives you more flexibly.
I play with this build all the time, the only addition is have a Tyranid prime with the Swarm lord.
When I play I only deploy the 2 units.
The Swarmlord and this guard are ridiculously resilient. You have 11 T6 wounds with a 3+ save. What I do is hop from cover to cover with the unit and get a 4+ save.
I have played this list for a while against all armies including DE and Grey Knight Mech spam, this unit always makes it to turn 3 and usually survives the whole game as once turn 2 rolls around the enemy has a ton more threats in their face.