LGW is closer than 25 miles to LHR as is LTN as is LCY as is Biggin as is Farnborough as is White Waltham as is....Blackbush etc etc
Surely all blocks of airspace are unique and what about the mix of traffic therein , it is impossible to compare LAX with say the London TMA ?
Don't compare then...how about just learn from them. I was merely making the point that New York has 3 MAJOR airports within 25 miles of each other (and if we want to be picky I am just guessing that LGA, EWR and JFK are a wee bit busier than LTN and LC and KB included). They have a system in place that manages to make it work. Is there nothing in that system that can't help control traffic in the SE. Nothing that might make the controllers job a bit easier? Is it complex? Yes. Does it go t***s up every so often? You bet...but at least there is something there to manage capacity. The debate in airspace capacity comes up every so often but you have to find a way to increase that capacity. Flexibility should come from lots of different areas...looking overseas should be one.
Yes the airspace the airspace over the SE has its own set of challenges and yes it is congested...but by saying it can't be done because it is unique basically ignores any other congested airspace the world over.