>>45329887They’re not the same, really. Although 2/3rds at 1.5 power is likely better. OHKO or 2HKO thresholds can mean the 100% accurate option gets the knockout 0% of the time even if it hits every time, while the less accurate move gets the key KO when it hits at least.
Of course there’s also the opposite where the less accurate option is overkill and it’s the 100% accurate move that gets the KO 100% of the time.
Basically you aren’t just doing an average amount of damage to an indistinguishable blob over an infinite amount of time, so they’re really not the same thing.