Enemy models can shoot at the building's garrison, provided that they can trace line of sight to the building and that it lies within their forward arc. Naturally, we assume that the building itself provides a certain amount of protection, so we treat the garrison as being in hard cover – shots are otherwise resolved normally. Note that the garrison unit is considered to be too spread out to be affected normally by attacks that can affect multiple ranks, such as bolt throwers – shooting attacks of this nature will only hit one model.