As a young man (teenager), I worked part time at a small butcher shop. They had a great business with meat counter, smoke shack and also processed hunter's game. No WalMart's, Costco's back then, just a normal grocery store in the neighborhood.
I trained on cutting up customer's wild game. Why....because if mistakes made, no big deal. Not like if a side of beef came in, mistakes with beef are costly. I was always scolded because taking too much time; picking hair, cleaning dirt-pine needles off, working bloodshot areas, removing silver skin, etc. It surprised me then how much "scrap" was tossed out. I used to save wild game "scrap" and bring home, cook for the dog.
So maybe poor meat yields are due to training mistakes with cutting game meat. And mix ups, from one customer to another, were common. Not with me but the other 2 young guys and they didn't care...but they didn't get scolded either. Those 2 would often save a few select cuts to take home too!
The two hunt seasons I worked there was invaluable experience, as for many years now I cut up my own wild game.