Yes but that's exactly my point. Because the Overground network does not
have nearly enough connections with other rail routes - Underground or
surface lines - any new lines or extensions should have as one of the primary
objectives a new connection with the London Overground service.

One of the many failings of the over-ambitious Crossrail 2 scheme is that the
planners intend the route to go deep into north London without connecting
with London Overground!

Living in Leyton, I am well served by the London Overground system, and I
use it as much as I use any other part of public transport in London. It is very
noticeable that far more passengers board and alight from trains at
interchange stations than at non-interchange stations.

Although the very rapid increase in patronage since the re-branding of London
Overground means it has been a major success, it is still working far below its
real potential because it does not connect with other routes.