The two processors that I use process each carcass individually. Smoked/processed products like summer sausage, etc can be ordered full-batch, meaning that YOUR deer will be used. If you only want partial, it may be mixed with other to make up a batch, but you get the weight amount you choose. I don't care for those products, and so I get my my meat, knowing how I cared for the deer after the kill.
My brother-in-law wanted to try a new processor once. I rode with him to drop hims doe off. The owner was sitting in the shade in a chair when we drove up. It was in the 60s, sun shining brightly. There were more than 20 deer eating out on the cement drive when we pulled up. He said his skinner was late coming in that morning. My BIL dropped his off anyway, and got it back a week later. He wound up throwing it all out as it wasn't fit to eat. I knew as we drove away that it would be at best, two hours before his deer was skinned/gutted.....