"At that time, partition was already agreed."
Partition was agreed under duress - you've had the statement
It was that whiocch caused the Civil War which was been the Free State forces which supported accepting the agreement on the understanding that the six states could be won later and the Republicans, who wished to continue fighting
The Free State accepted that partitioning had only been accepted under threat of war - they even accepted that The British Government had blackmailed Collins into acceptance via his affair with the American, Lady Lavery.   
We really are done with this Keith - you denied any threats were made, you've said Lloyd George's statement was a fake (disproved by Terrytoon); you've said he was referring to something else entirely - now you seem to want another go at something else.
Sorry - for you the war is over Tommy.
Go and find something else to obsess about.
Jim Carroll