Morus Kyoob designed his renegade robots to a flexible, interdisciplinary concept: sharing the litheness of a Sentinel with the protection and stopping power of a small Titan.
In spite of their monolithic scale, he built them to be as frisky as any Space Marine in power armour...
... the very unexpectedness, and seeming wrongness of their mobility was useful as a terror weapon; and seemed to whisper of wantonness, and heresy...
"Is that why he gave them pointy toes??"
"If you'd seen those pointy toes do the things I've seen, you'd wipe that smirk off your face. I saw a Headie II toekick a dumpster seven kilometers. I saw the driver kick a minibus, and it took five Space Marines to lever it off the toe. That's when Morus stopped sharpening all the toes in postproduction."