I think that it would be cool to have a looksie at why perks are a foundation of a unit. Take a level 50 mythic, and get one without any perks, and one with perks. Then have a comparison of what happens. If a 50 leviathan cant protect the horde or regenerate to full in between encounters, its very weak compared to one that can. Any unit without crits Will be certainly dead in a one on one, with lower stats than the enemy. Make a set roster of units, one without perks and one with perks, all level 50 mythics, and see how much better that unit is. And also, what perks dont go well with others. Basically, what you can and cannot do, with perks affecting it.
Or just a lore contest. Like what happened at the start of the infection, and why there are so many zombies that are the exact same as others. Like biohazards are plentiful, even though they were in a hazmat suit. And how so many brutes mutate the exact same shape and form, with the exact same size of wood stuck in his skin.