THE SMART TRICK OF BUD NAKED FLOWER THAT NO ONE IS DISCUSSING

The form of Latin S arises from Greek Σ by dropping one out of your four strokes of that letter. The (angular) S-form made up of a few strokes existed like a variant of your four-stroke letter Σ previously within the epigraphy of Western Greek alphabets, and the three and four strokes variants existed along with each other in the classical Etrusc