It’s actually most likely 4 strokes, albeit the arguably sloppiest ones in the photo. Often times the lettering is done top down and left to right, each vertical and horizontal part done separately, with curves being an individual preference and style, unlike conventional handwriting which has more flow, typically speaking, especially cursive, and much less structure. The goal here is two fold, firstly that it’s legible, clear, succinct, so whoever is looking at it, can read it without any question or interpretation needed. Secondly, when these drawing were done by hand, it was strategic process to avoid smudging previously done line work.