[pfreivald]

I simply don't see an Autonomous Stack happening except by single robots picking up all three crates--and that's going to be a difficult task only accomplished by the best of the best.

The totes are about 21 feet apart, so you have fifteen seconds to acquire, move ~7', acquire-stack, move ~7', acquire-stack, move ~7' to get in the zone (Auto Zone!), let go, then move a very small amount.

All while avoiding your alliance partners and the Containers.

Possible? Sure.
Probable? Only at the highest levels of competition.