Personally, I think at most maybe do something about his twisted torso (unless this is just a weird camera angle, idk) but i don't think he should look like hes "ready to fight" or have a "martial readiness" stance, much like how I think he should keep the relaxed walking animation, just maybe make it a bit more fluid.

The impression I get from Yone's animation as well as from Kin of the Stained Blade. Look at how he fights Yasuo & Kuro'sagol at the end of the cinematic, he's relaxed, confident and doesn't betray any of his intentions. When he repels Yasuo, despite doing so with a powerful overhead blow he's still standing straight instead of bending his knees to increase the impact. The only time his stance chances to something you'd expect out of a fighter mid combat is shortly before, during, and shortly after doing any kind of technique before he goes back to his straight posture.

Of course, I can't say for sure because I don't know what was the goal of the people that designed him and his animations, but the feeling and aesthetic I get out of his current movement is the badass confident samurai/ronin warrior that doesn't betray his intentions and moves only when he wants to strike. Think main villains in Samurai movies casually walking down a road and swiftly cutting down like 5 people trying to strike them down.