You misunderstood me.
I was saying that the borders were chosen to leave as many as possible on the correct side.
I am sorry if my wording was ambiguous but I had already stated, "The boundaries were deliberately chosen to include as many unionists as possible within the union, and to allow as many nationalists as possible to be outside the union."

I do not accept your version of that history.
If it was true, would hundreds of thousands of young Irishmen, all volunteers, have fought for Britain?
Compare that to the number of rebels.