The problem people seem to be having is that this is Alternate History.com, not RandomFlags.com. People here care about the backstory and the plausibility behind scenarios, and you saying that the UK might break down into the English regions in 10 years is almost impossible.
Now, let's phrase your questions differently:
Suppose the plans for regional assemblies in England pass, and each region gets it's own assembly then it is reasonably to suppose that they would adopt symbols - coats of arms, logos, perhaps even flags. How do you think that would work? Some like Yorkshire & the Humber or the North East would be easier as they have fewer component parts, London and East Anglia also have existing symbols. But what about the rest? Is there some way to combine all the heraldry and tradition of the South East (say) into one symbol for a South East Assembly?
So, people of AH.com - what say you?
That is how you ask, and if I have time I might have a go later.
EDIT: Why oh why does randomflags.com not exist ??