I've met maybe 1-2 people in my whole life who were clearly beneficial 'A' from the get go. There's also a weird 'A' that tries very hard but causes more pain than inspiration. Meaning, they're clearly smart but think that's all that's necessary to be useful. I once worked with an intern from MIT who came in and immediately submitted large PRs everyday that improved the algorithmic complexity for a bunch of functions…
Related, but the best quality to have in a startup is knowing when and what corners to cut instead of going on these side quests.
And the management tier of the startup will too easily color the signal by the flavor they want to see.
My latest take on this matter is to separate speed as in fast from quick. Quick is the thing you want and almost always good. Fast is what usually gets lauded and measured but fast just gets you large volumes of fuzzy signal faster.
(quick means that something can take time and be measured, not rushed, things can bake, and the feedback loop is responsive quickly throughout the loop. while fast is looking at wall clock time and goaling on the end-result yield from the loop. i think it’s very misguided. things very often need bake time)