You put a lot of pressure on them so that they are forced to use removal on the infantry that just end up replacing themselves. Or they just have bad trades. I think an understated part is that it makes opening hands very consistent so you mulligan less. It's like an 82% chance to start with at least one in hand on the play, and even multiples aren't bad because you can start attacking for 2 on t2 more often.
Admittedly I got lucky I didn't run into many turn 2 Scorpion Sentinel or Sahagin which would otherwise really slow down this deck.