Exactly as you said, nature is the most annoying matchup you can face, won very few against it but every deck has this hard counter imo. As for the acolyte I only added it as a good clearing card against decks that rely heavily on board building early on and a 4/4 for 2 mana is really good for this purpose. I was trying to find the best budget option for this and I came across acolyte. Feral Shapeshifter would be a decent replacement too but you sacrifice clear for more speed and face damage potential. Contract broker as you said really good for hidden in general and also good against annoying shields with war and light.