This is super deceiving and I'm kind of upset they posted this image, knowing it would mislead people not familiar with the game. The AI sits around during lulls at <30 APM - meanwhile MaNa and TLO were literally spamming keys to keep their fingers warm, not actually doing anything.
During the fights, the critical moments in when MaNa would top out at ~600 humanly inaccurate APM (this is 10 inputs per second), the AI would jump up to over 1000 - we don't know exactly what it was doing, but it was presumably pixel-precise. Meanwhile the physical inertia of the mouse is a challenge for humans at that speed - imagine trying to click five totally different places with perfect precision in a single second.
APM gets inflated by counting several single actions as multiple separate actions. For example a Zerg player may want to turn larva into 30 Zerglings, they do this by pressing one button and holding it down as the UI repeats a separate action for each larva transformed.
By comparison selecting a single stalker, and having it jump to a new location is much more effort, but counts as fewer actions.
A huge part of a human's APM is meaningless spam, for example right-clicking the same unit multiple times to attack it, or setting the same waypoint thousands of times in the early game when there's nothing to do. The computer might be at double the human's effective APM, if only we had a credible way to measure that.
During the fights, the critical moments in when MaNa would top out at ~600 humanly inaccurate APM (this is 10 inputs per second), the AI would jump up to over 1000 - we don't know exactly what it was doing, but it was presumably pixel-precise. Meanwhile the physical inertia of the mouse is a challenge for humans at that speed - imagine trying to click five totally different places with perfect precision in a single second.