That was an interesting answer to the buttons on the coat sleeve question. Regardless of where you have buttons on your coat sleeves you can wipe your nose / brows with your sleeves, you will just have to twist your arm a bit.
Failing that, there is always the lapel of your jacket if you are in desperate need of a quite wipe. Somehow I do not think buttons on sleeves would have much averted scruffiness in Frederick the Great’s army.
My thoughts were that the buttons on the coat sleeve even though not functional these days were originally intended to allow the wearer unbutton his sleeves and roll them up. This was primarily to allow a gentleman avoid getting horse sweat on his coat sleeve while horse riding.
To this day, a number of bespoke suits still have working coat bottoms and an affectation is for wearers of bespoke suits used to be to leave one of the buttons unbuttoned to indicate the bespoke origins of the garment. Not so much these days as a number of people get their tailors to alter off-the-rack suits to have working coat sleeve buttons.
It’s very clear when you look at men’s coats from the 17th and 18th centuries that the sleeve buttons were functional. Both civilian coats and military coats (still basically based on civilian fashions) had cuffs which could be folded down to provide warmth and weather protection or folded up to free the hands, just as lapels, tails, and collars could be folded over/up or back/down for the same purpose. All of these various flaps had buttons placed to keep them in the selected position. By the 19th century, these were mostly gone from civilian fashion, but were retained as non-functional decorative elements on military uniforms.
The sleeve buttons stayed on cuffless men’s civilian coats first to make it easier to put on coats with tight-fitting sleeves (late 17th century), then later simply as a fashionable decoration (read “but we’ve ALWAYS put buttons on them”).
My impression of the army of Frederick the Great (or any contemporary army), was that, even if they cared, no-one would have bothered spending extra money buying and attaching buttons to stop soldiers from wiping their noses on their sleeves when a few blows from a sergeant’s cane would do the job much more effectively and cheaply.
Functional sleeve buttons on a suit jackets are a sure sign of quality and hand-made attention to detail. Many bespoke suits come this way. I believe (but am not completely sure) that this detail is referred to as “physician’s” or “surgeon’s” sleeves. The idea is that the sleeve can be turned up rather easily. I am sure that the origin is not exclusive to medicine.