@Hugin&Munin
One thing that I've included as a possibly-fair and balanced addition for the Human Team was to have Neuro-Fiber be a perk. From the game design document, if Neuro-Fiber is integrated as a perk, what makes it fair for the Zombie Team is that Humans don't gain Body Armor automatically; it must build up over-time. Although players that have this perk regenerate 0.5 Body Armor/ second, which equates to about 30 Body Armor/ minute, the maximum armor that can be regenerated is 50 Body Armor, which is fairly-low, and Zombies can tear through that easily compared to if the player had an instant 100 Body Armor.
You are right, I haven't considered that the Zombie players be new to the game, but if they were new, their goal isn't that hard or complex to understand compared to what the Human players have to do. They have to barricade, have healers, have proper equipment, have the best-damaging weapons possible in their current wave, etc., while Zombies only have to worry about being able to run at something and slash at it.
I will consider the idea for adding more to the Zombie Team to make it fair for players that do purchase Neuro-Fiber as a perk (if implemented), but if it gets implemented as equipment or starting equipment, that's when things get tricky. In anticipation of this, I'm revising the Neuro-Fiber GDD and adding a new one later on to satisfy the need for armor at the beginning, while keeping a balance between the Human and Zombie Teams by coming up with possibly-balanced additions to the Zombie Team.