Federalism and the Balance of Powers

Federal advocacy envisions a government where there is balance in the division of powers between the national government and the states.
If there is so much power that would be retained in the national government, even if there is division of powers and even if it is named as a federal government, the system is still a unitary and centralized system.

On the other hand, if the constitution devolves so much power to the states, leaving the national government almost powerless, the system is still unitary system because the states would become imperial states. It only increases the number of unitary states.
The key is balance. There must be proper division of powers so that there would be less likelihood of abuse on the part of the national government or the states.