Tom Anderson wrote:

What i don't get is why the off-peak pattern runs all through trains to
Bank, reversing *everything* from CX. There, the density of trains is much
lower, so the track issue is surely irrelevant - even with the awkward
layout, you could surely run all trains to CX, and have space to reverse
Banks? Since in the off-peak the Bank/CX demand ratio falls dramatically,
this would serve people much better.

Yes but in the eventual split Morden goes with the City, so preparing people
for the idea that Charing Cross is accessible only by interchange is a good
long term strategy for making the split acceptable. One can't make a strong
opposition case to the split on the basis of these throughs being lost if
they've already been lost.