Tall Nonmen --> FUCKING TALL SRANC
Bashrags, man.
NO NO NO--The Bashrag are totes diff yo! The description of them when they were hiding in Dagliash gave the template--they are the Animated Offal! What's that fancy A-word for garbage, the one philosophers use; blanking out on it right now.
Agree with MG on this one. Bashrag are walking chemical weapons, and the Tekne bomb was set to disperse the plague "in the right direction" -- that being south. The Ordealsmen (led by the disillusioned Proyas) that are not infected must continue north, bringing the battle deeper. The Great Ordeal was purged of those too weak to go forward.
The Tall, meanwhile, seem like the longterm Nonman-version of Cniaur, who at 60+ years old is, if anything, more formidable than he was 20 years ago. The text describes "heroes as belonging to the World more than any other, since bravery is impossible in hell and unnecessary in heaven" (not verbatim but damn close). This is because in order to be a genuine Hero, one must defy the odds of the world/antagonist killing them (or more abstractly, obstructing their goal). After all, what else is the typical notion of a hero? A survivor. The Tall are the most Heroic Nonmen, which is another way of saying that they clung to living (surviving) more than any other.
Those Ordealsmen "naturally selected" to bring the battle deeper into Golgotterath are...
The Great Ordeal marching into to the tunnels in the Ring Mountains. Fighting the sranc in the tunnels, makes for plenty of natural choke points. Their new lowlight/dark vision means that they'll be able to see just fine and won't be ambushed. Blocking off the tunnels with piles of sranc corpses, retreating, rinse wash repeat. Imagine pitch blackness and the Ordeal/sranc hordes fighting underground.
...being primed to do exactly this.