We've wandered far afield in this thread, let's put it together and see what we have now that a few more chapters have gone by. We don't know everything about the Smart Ones, but there are enough clues and observations to assemble a beginning personality profile.

We have observed:
- increased strength
- increased speed
- increased stamina
- some ability to retain language comprehension and usage (Ink in the Tower)
- the ability to recognize the relevance of technology (the tracker trap)
- the ability to use self-restraint (live prisoners being taken)
- related to self-restraint, the adult skill of delayed gratification (the arena prisoners, saved "for weeks" between events)
- communications at some detailed level (giving of orders)
- planning and executing coordinated attacks (Ink observing above the vehicle ambush and on the rooftop during the War)
- enforcing discipline in the creature lower orders (he bellows, they obey - why I don't know)
- the ability to manipulate technology (the keypad and possibly driving the blocking vehicle at the convoy ambush site)
- while not proven, I agree that the Behemoths were stationed intentionally at both the water pumping facility and at the military base. Both are known high-value assets to humans (other survivor groups had utilized both) and I could see leaving a Behemoth as a walking trap. This would indicate long-term strategic thinking if true.

Have I missed anything?

That is indeed an alarming level of intelligence in your enemy.