The pitfall for the average viewer/player is to take these mantras and apply them directly to what they see. They see a game where T apparently overcommits after winning an engagement at his 3rd, and wonder why he didn't take a 4th instead. Surely, this is a mistake of not getting more ahead!
An expert player might look at the same scenario and see an entirely different picture. The problem was that he scanned a 15m timing instead of a 17m timing for the Hive, so he was actually behind in that engagement (he should have decisively won with the Z's gas locked up elsewhere!). And that Broodlords would be due out in 2 production cycles, but it takes 3m for him to break-even on the new mine, and he would miss the window to secure enough of an advantage to push the game into a low-econ trade phase.
My point is that real game understanding is extremely specific. It's all about the actual state and timing. To go back to the article, that's where the marginal advantages are gained - by understanding and controlling how these extremely specific scenarios play out. The larger ideas about strategy that everyone loves fall out from the analyses of these interactions. But "getting" the general idea isn't the same as actually _getting_ it when you work out these scenarios and timings yourself from extensive playing/testing. So heuristics are really only part of the picture, the much larger part is a precise understanding of the system at work.