I'd say that to a certain degree all of us do this, even if we're not all consciously aware of it. The unintentional use of this "trick" in my view is as obvious as when people imitate others. To the more extreme end, as you describe here, it can be the deliberate and wilful act of simulating the thoughts of another person for apparent guidance in times of stress.

Overall, I'd say this is just a version of thinking of what a "prudent man" would do, or some might even use the term "straw man" (to separate themselves from reality for the purposes of winning an argument), and for me I have spent much of my life referring to the guidance of others, including a long list of gym trainers - both real and simulated.

The danger, however, is that the subjective nature of the mind running the simulation does create a bias, even if you can't see it. Just as my simulated gym trainer will advise me against eating junk food, ultimately it is my own motivation to follow through on the final act. It might be a "trick" only because it is actually you making the decision without admitting it, but that doesn't mean your decisions are any better and don't ultimately suffer as a result in times of fatigue.