Melt 2 tablespoons of the schmaltz in a 12-inch skillet over medium heat for 1 minute. Add the onion, celery, and 1/2 teaspoon of the salt and sauté, stirring frequently, until the vegetables begin to brown, 4-5 minutes. Finish with half of the sage leaves and 1 teaspoon of the minced thyme leaves and cook 1 more minute. Remove this mixture to a small bowl to cool for 5 minutes. Kill the heat and leave the dirty pan there, you'll need it again.
Place the turkey in a large mixing bowl along with 2 teaspoons of the salt, pecans, stuffing mix, marjoram, 1 1/2 teaspoons of the black pepper, nutmeg, parsley, egg, and the cooled vegetables. Thoroughly combine with your fingers. Scoop the meatball mixture with a tablespoon into 24 equal portions (about 33 grams each) and place them on a sheet pan. They don't have to be perfect balls at this point. Refrigerate for 30 minutes (or cover and store overnight to finish the next day).
When 30 minutes are up, line a half-sheet pan with a layer of paper towels, place a wire rack upside down on it, and stash near your cooktop. Dump 1/4 cup of the flour into a pie pan or shallow plate. Roll each meat portion into a ball, lightly coat in the flour, and return to its sheet pan.
Heat 2 tablespoons of the schmaltz over medium heat in the pan you cooked the vegetables in for 1 minute. Add 12 of the meatballs and brown, flipping them around occasionally until the internal temperature reaches 145℉, about 8 minutes. You may have to lower the heat as needed if the bottom of your pan begins to get too dark. Remove the meatballs to the half-sheet pan lined with paper towels and the rack. Add another 2 tablespoons of the schmaltz and repeat the process with the remaining meatballs.
Add another 2 tablespoons of the schmaltz to the meatball pan and sprinkle in the remaining 2 tablespoons of flour along with the remaining sage and thyme. Use a whisk to help scrape up the browned bits of fond left the pan to make a paste with the schmaltz and flour. Cook this for 1-2 minutes until golden brown. Slowly pour the wine and stock into the pan and increase the heat to medium-high. Continue whisking and scraping the bits from the bottom until the mixture comes to a boil. Season with the remaining salt and pepper. Reduce the heat to low and simmer, Whisking occasionally, until thick enough to coat the back of a spoon, about 8 minutes.
Add all the meatballs into the gravy and continue simmering until the meatballs are cooked through (160℉), another 3-5 minutes.
Serve over a bed of egg noodles with a sprinkling of chopped parsley and sage.