ok...so your basically cutting off the primaries just radial "thumb"(trying very hard to remember my anatomical directions)......which in laymans is the part of the buffalo wing that is discarded. i think i follow! for some reason i imagined pinioning being something more of stapling their wing closed and that just made me wonder! but that is great!! i am gonna go home and take a look at my baby chicks, got a couple that are less than a week old. Not that i plan on pinioning anything just yet, but will give me something to look at!
chickens will obviously be a good bit smaller, but should give me something to look at, right?
yup.. pretty much if it's poultry.. it has the same anatomy for the wing.. you can pinion chickens, ducks, turkeys, quail, pheasants, peafowl...
no point in trying an emu though.. their wings are useless.. and built a bit differently!

some people will claim it's cruel... but it's no different than removing a dew claw on a day old puppy.. a bit of a squeek and it's over.. no blood unless the bird is a few days old.. and even then it's barely a drop