I found a small and very simple solution if anyone is interested.
On my "On Pathfinding Path found" event, I added a subevent that checks if the Zombie is currently overlapping another Zombie. It checks which Zombie is the closest and which is the farthest. It then assumes the Farthest Zombie is behind the Closest Zombie and Stops its Pathfinding. It then moves the Closest Zombie along the path, assuming its also not colliding with another Zombie that is even Closer.
It's not too buggy and is better then nothing for now.