You're talking about instrumental rationality, but you're replying to a comment which seems to be implicitly using "rationality" to mean epistemic rationality, which is almost entirely unrelated to the instrumental rationality you're talking about. Epistemic rationality is not relative to goals, it does not depend on value systems, and it is not subjective. So your comment is irrelevant to the comment you're replying to.

There is a weak connection between epistemic rationality and instrumental rationality: plans based on false beliefs are more likely to have undesired results. (This is why sometimes people lie in order to manipulate others' actions.) But often they don't.