Nigeria isn't working at the moment, and we all know this. All of our numerous ethnic groups can't possibly go their separate ways, so the most pragmatic option is to think about synergies... Aligning with others with whom you share same core fundamentals (values, way of life, socio-economic indices, and worldview). For this reason, let us assume that the contraption called Nigeria would be split into two tentatively named entities - Republic of Southern Nigeria and Arewa Republic. How would you apportion the current states?

Here we go..

Southern Republic of Nigeria
The entire South East
The entire South West
The Entire South South
Kwara
Plateau State
Benue
Christian Taraba
Christian Adamawa
Christian Kaduna
Other willing non-Fulani Christian minority ethnicities of the North in Bauchi, Borno, etc.

Arewa Republic
The entire 'core North' as we know it, minus its aforementioned non-Fulani Christian minorities)
Kogi State.

There are many reasons why the irksome Kogi eminently belongs and fits into the Arewa Republic. Hopefully, someone can pinpoint it.