If the butcher added fat to your venison it would not be the best for snack sticks. You would probably have to add more fat for sausage.
I grind my own and don't add any other fat to it. When I make sausage I add 30% pork fat to the burger. For snack sticks I do not add any fat per se, but I will throw in 20% regular grind beef burger.
So to answer your question. If it went to the buthcer and he larded up your grind, then you made sausage and added more fat, then yes it will make a difference. I like lean meat for snack sticks so the same thing would apply.
HA