braum was designed to be a warden yes because he protects his allies at his own risk, yasuo however has the thematic of being an exiled wanderer who from my perspective shouldn't have a supportish ability (im not saying its bad but from a thematic view it makes less sense) yasups wind wall should be a self protecting ability where the wall swirls around him and blocks attacks that target him or those within a certain range of him.
You figure, Braums shield ability is only slightly larger than his hitbox and in fact moves his hitbox to be larger in the direction of the shield, however because its merely braum acting as a shield he would naturally take full effect from anything he intercepts.
Now yasuos wind wall in my opinion should be similar but isn't, its a stationary wall that blocks ALL ranged abilities (another nonsenseical thing), the "wind" that makes up this wall is apparently more or less magical in nature due to his ability to "strike so hard he generates areas of intense wind or pressure" this would explain yasuos ability to seemingly throw mini vortexes after 2 strikes of his sword, in a logical view however even this generated wind wouldn't be enough to stop a completely magical projectile, yet his wind wall can stop almost every ranged ability in the game, (there actually are three ults I believe that can pass through the windwall don't quote me but ive seen certain abilities go right through as if it wasn't there)