In Starcraft 2, it would be fantastic to individually control all 16 marines in your 2 medivac stim timing, pulling them back when they become the targets nearly instantaneously, perfectly shuffling them into/out of the medivacs, while focus-firing the defenses. Another example would be a reaper rush, a beastly AI could in theory micro 5-7 reapers individually, potentially breaking the game as human fingers/muscles/nerves have limits that CPUs and GPUs do not have.
The latter concern, about sheer speed and potentially limiting APM of the Starcraft 2 AI, is a very interesting one. It would be interesting to allow the AI to match the average APM of the Global Finals players, for instance, which might be around 300 actions per minute. If the computer was allowed to utilize 3,000 actions per minute, it could surely perform much greater feats of micromanagement.
The largest edge I see human players having vs the Starcraft AI would be something strategic, get a sense for how the AI plays then pull off a specific strategy which counters it. It may not work well in the current human-meta, but perhaps the AI will have its own meta that you can out-think it on?