Tons of species can live with a alligator snapper, just don't expect them to live
You would have to have a massive pond with a good depth to keep the snapper out of reach. No matter what kind of fish you put in there, these guys diet consist mainly of fish and they are one of the best ambush predators out there. Not worth it if you ask me.
What size is the turtle?
I had a 3 inch alligator snapper and it couldn't even catch the feeder guppies I gave, they eventually got too large for the snapper to bite.
also kept jack Dempsey with the turtle, it chased the fish for about a week and then left all fish alone and ate pellet food.