Of all the Igbo groups that have claimed to be of Benin origin, that of Etche by some pundits happen to be the most far fetched and ridiculous.
The claim was made by Achonwa(whose name is even popular around Owerri) in his 1980 piece on the history and origin of Etche people. It was seconded by Onyema(2000) they were both hypothesis and even Achonwa was honest enough to say so and offered an alternative Igbo origin of the people alongside.
Achonwa made his claims arbitrarily and without facts... he does not site any town's oral traditions as a reference. It's interesting to note that Etche is not part of the Akalaka group neither does the Ogba or Ekpeye traditions list Etche.
In his last book "i remain your humble servants" the former Oba of Benin, Oba Eradiauwa stated it clearly that they do not know Etche people, that the Etche are Igbo.
Etche is made of six clans,
Etche is not a homogeneous group as you will come to see down the article, it is made up of different people from different areas but the dominant group in the region claims descent from a man called Okolokoche or Ochie(which later was corrupted as Echie/Etche)
Ochie is a semi mythical figure was said to be the first man, the ancestor mankind, who settled at a place called Igbo. His two sons founded Igbo-Udo (Igbodo) and Igbo-anwirinwa, migrants from Igbodo founded Igbo-Echie another town, the Igbo clan remains the most senior and oldest clan in Etche.
What many don't know is that the same legend of ochie being the first man and we are all his descendant are found in all the Ngor and Owerri area which is why the term "nnam oche" is popular...
Actually most scholars agree that the Etche migration and the Uratta were one for many parallel reasons which you would see.
In Owerri West LGA there is a town known as Okoloche, in Etche LGA there is another Okoloche, both towns lie in the same migratory route between there and Igbodo.
The collection of Okoloche, Ihiagwa, Eziobodo and Emeabiam are known as Oche and referred to themselves as Nde oche with Okoloche as the center.
All the rivers in that region down to Etche has a suffix oche in it's traditional name..Imomirioche, Otamirioche, Oguoche, Oramiriukwaoche etc.
From Igbodo most of the clans spread to other areas but some went back up North to settle and that is how Ngor clan was formed(Elelem, Alulu, Ntu, Umuneke, Imerienwe etc), they founded exact settlements in search of farmlands and hunting grounds such that as there is Umuoye, Umueze, Ozuzu, Elele, Umuechem are in Etche equally there is Umuoye, Umueze, Ozuzu, Elelem and Umuechem in Ngor/Okpala to mention a few. Some of these settlers went further to settle, Ulakwo which is one of the 6 clans in Etche settled in what is in Owerri North LGA, and in Enyiogugu Aboh Mbaise. Also Umuoye in Mbaise and Lagwa are part of the same movement.
In the 17th century there was a series of bloody land disputes in Uratta region because of population expansion the first bloody war was between Egbu against Awaka and Ihitta. Led to the dispersal of people from these communities such as there is Ogida and Egbu in Etche, people moved further to settle in Umuaturu, Egwi and Umuakuru (Akuru is the ancestor of the Uratta)
Another war was between Obibi and Ihiagwa during which Nekede joined to aid Ihiagwa.
The end result was that Obibi splintered with some settling in Mbaitoli while many moved down to Etche
All these stories show an interconnectivity between Owerri area, Ngor/Okpala and Aboh Mbaise with Etche/Omuma,
Almost all the towns in Etche has its namesake in Imo State, (and this is common in tracing route in Southern Igbo because when people settle they go with the names of their original communities)
E.g there is Afara in Mbaitoli, Afara in Etche and Afara in Umuahia. Umumbiri and Ebieri in Etche and Mbieri in Mbaitoli. Ihie in Etche and Ihie in Imo, Obite in Ohaji and Obite in Etche, Isu in Imo and Isu in Etche.
As a show of kinship... the philosophy of chi is the name in Owerri and Etche, and Etche has a deep understanding of each persons chi such that Echie is the only part of Igbo land that had specific and elaborate chi shrines.
The whole region of Etche, Owerri, Aboh Mbaise and Ngor/Okpala practised the culture of Mbari moulding
Amadioha that everybody has come to associate with Igbo culture is actually known only to the Southern igbo and originated from a town oracle in Ozuzu Etche, it was agents of these oracle that went up North with their families and founded Umunoha in Mbaitoli. Of all the deities of Etche pantheon none bears any semblance with Edo groups...they are all Igbo, Amadioha is Igbo with an Igbo meaning. Thus Ochie/Echie can be said to be the oldest Igbo group in that area and why it is a priestly clan, most of the religious and cultural practices that distinguish Southern Igbo originated from that region and not vice versa as claimed by beninophiles e.g Mbari, 8 day market week, ituanya, ogba-ige, Amadioha cult, Otamiri cult, Afo-ukwu, cluster settlement etc. The legendary ancestor Ochie is held in par the same way Eri is amongst Northern Igbo folks and Ife Nta amongst the Eastern Igbo axis.
So to say that Echie migrated from Benin is at best very laughable, this is an age when if you make claims you back it up with evidences or sound logic and maybe people will begin to find reason in your points