Why not extend it to include the option of 'independence' for Cornwall, as a celtic outpost, or resurrect the historical early medieval Saxon and Danish kingdoms ? Why should the rest of England, particularly those parts more than 200 miles from London, be dominated by the South-East ?
Alternatively, and more realistically, why does everything have to be subject to 'balkanisation' ? Why try to over-emphasise local differences and play down common interests ? The more you try to partition things up, the more distrust and conflict arises.
We didn't have an English Empire, we had a British Empire. It is much better that the United Kingdom is a member of the EU, than four self interested and far smaller, ( and therefore less politically and economically significant ), regional identities. How many Olympic medals would each region get in isolation ? Together we amount to something, separately we are much diminished, especially ( ironically ) Scotland and Wales.
I am proud to be able to claim I am a Hampshire man, yet at the same time I am a Lancastrian. Even more so I am English and British, a citizen of Europe, and most importantly, a Human Being; part of a population of about 6 billion similar, unique, individuals who should be learning to get on better with each other.