In a heavily planted tank, if the plants are growing, the ammonia from the fish will very quickly be consumed by the plants for the nitrogen. But, in any case, nitrogen converting bacteria will grow on all surfaces in the water. As the ammonia load builds up-as more fish are added-the bacteria colonies will expand to match the available food. All of this means a tank that is heavily planted from the start doesn't need an effort to develop a bacteria colony, as long as the plants are growing before any fish are added, and the fish are added a few at a time. But, a lightly planted tank, in which a lot of fish are added at one time must have been allowed to grow a bacterial colony before the fish are added. Obviously, one big fish is the same as lots of tiny fish, where ammonia generation is concerned.
That is my opinion.
That is my opinion.