Even if they were based on the form of animals, they still were in an immature or incomplete state.
They had lower Life Energy and their form was much smaller, resulting in their capabilities not yet reaching their full potential.
They would only truly reach that full potential when they became a high-grade Spirit or Evil Spirit.
It would only be then that they would have reached their full growth, both physically and mentally.
It would not be until later that they would be able to gain wisdom, reach their most ideal size and form, while having their innate abilities and senses fully awakened.
It was the same when it came to how most Spirits and Evil Spirits would not usually gain some form of power or innate ability until much later.
Even if they did happen to gain something a little earlier than the others, they would still have an ability that would be in a state where it would not be as powerful as it should be.
