I've done these brain tan hides about every way possible. Wet scrape, dry scrape, lye to slip the hair, no lye, flesh on a beam, flesh on a frame, smoke each hide individual or many together in a smoke box, yadda yadda. Many ways will work, and the consistency of the finished product changes a bit with each method. Personally, flesh them on a frame, scrape them on a frame, no lye. Pappy nailed it. When done right the epidermis and hair shave off in little ribbons instead of loose hair flying everywhere. We built a big box, about 6 foot tall and 6 foot wide. Maybe double that deep and we started smoking dozens of hides at one time, without fear of any getting lit up. Yours look really good! nice work.
ps. Sadly ours here in Texas are rarely if ever that big. Barb wire scars galore.