I read newspapers (online) daily and i take in people's comment concerning Nigeria and i found out that its mainly the Hausa and few Yoruba people that talk of one Nigeria.
i have never heard any Ibo man talk of 1 Nigeria, they are against it and are secretly praying for Biafra
i wasn't born during the civil war, but from the day i was told the story by my mother, i've always wished Biafra succeeded.
i ask myself sometimes why people talk of war when regions talk of seceding, for example if Biafra is declared as a country tomorrow, why would the Yoruba and Hausa people declare war on us? its not as if this country is working & i don't think it can ever work with the Hausa mentality of 'born to rule'.
A lot of my friends say the Hausa popeple will suffer if Nigeria is divided, but i beg to differ, they may not do as well as the other regions but they have farms (i think they are the ones supplying food to other regions).
i pray and sincerely hope that Nigeria is divided(peacefully) because it is easier to rule people with similar culture, belief and religion. The 3 regions will be better of separate than together.
Can anybody tell me the advantage of 1 Nigeria

There is no "one" Nigeria.

The best you can do is split North and South, or perhaps, North, South and Biafra, and then join with Ghana, Senegal et al. into a sort of East African Union with no trade tariffs but with national sovereignty and a common military and border force.