Coalition Honor Guard forces the opponent to target it with spells like Skred or Ephemerate-adjacent removal when choosing targets, which can waste their limited removal on a 2/4 body and protect your real threats. It's a low-risk, low-cost inclusion given the deck's reliance on targeted effects. Salt Road Packbeast is too slow and doesn't affect the opponent's card-advantage engine of Mulldrifter and Archaeomancer, so it comes out. Given the light nature of this swap, most of the deck stays the same since your elf ramp into big threats is still the primary plan against their grindy value shell.