As I mentioned before, everything in this mission boils down to surviving the first 2 weeks. Logistics doesn't help with that, so it's useless. Surviving these 2 weeks is the only difficult part of the campaign, and therefore all the character development is geared towards it. I remember seeing a walkthrough of this mission where the hero completed it WITHOUT using any magic, but I don't even want to comment on that.
Even though the racial ability doesn't bypass immunity to plague, there won't be any creatures with plague in the early stages of the mission.