There was a long thread on here a few years ago by a fellow named Mark (he went by the moniker “S. Cerevisae”. Mark knew more about yeast than the rest of us and he advocated the Shaken not Stirred approach, because the yeast are pitched at their highest vitality point, which was more important than merely number of cells. That has become accepted as a favorable approach, but the yeast are hardy critters and they will make beer with or without a stir plate or shaking vessel. I like the SNS method when making a starter, but a stir plate clearly works, too. However I prefer repitching slurry, frankly, when I have that option....