BG are both predator AND prey.
Therefore, getting them stocked in the perfect size and numbers is tricky.
One of the (many) things I have learned at Pond Boss is that no pond can stay in balance for an extended period of time. I thought you could just follow the expert advice and create your pond and fishery like a well-constructed house.
I had to read a lot of posts to realize that even our experts are constantly tinkering with their ponds in an effort to just improve the balance of the fish population.