That’s true; the 3DS health bar has 48 pixels, leaving a margin of error at just over 2%, much more precise than the 4% in the asker’s example. I guess Smogon thought that pixel measurements was too extreme to expect most players to do when playing on 3DS, but that damage calcs weren’t (I mean, some of the more advanced Pokémon sets use careful calculation to ensure it has just barely enough to outspeed, KO, or survive against specific threats, so I guess it is reasonable to expect in some cases).