So uh,
@DarkDragonMedeus answered my question, and here's really what I got from it.
The strategies that a character with no IC moves or decisions depends mostly on their intelligence. We obviously don't assume that they have some form of precognition or information analysis that allows them to suddenly know the best possible moves they can make, but, based on their intellect, we can form a general inference on their standard stratagem in a fight. For example; we'd assume that a character like Minecraft Steve/Alex, based on their Gifted level intellect, would prioritize basic self-defense and resort to the items that they know have the most "utility" among their toolkit, due to their intelligence reflecting that they can make such a basic choice, instead of assuming they will instantly form the greatest plan evahhhhh.
How exactly we would judge this for a Genius level character like Terrarian I do not know, I believe that's up for discussion.