End of the day, the BR units were sold to the ROSCOs at bargain basement prices, so it’s their problem whether they are able to flog them or not.
Whatever way one looks at it someone is paying for all these new trains, in an industry where costs are renowned to be poorly controlled in some sectors. The trains are not being built, tested, commissioned and staff trained for free.
I can understand that there may well be a viable case for replacing DC motored stock on the basis that it does have a costly maintenance regime and is now at the point where modern packages are regarded as more reliable. I could even add the 365 to this, just about, on the basis that it too has an obsolete traction package - although as a modern modular train retractioning should be fairly easy and cheap to do.
However any idea about replacing stock like 357s or Southeastern Electrostars in my view is totally bonkers unless there’s a defined set of old stock which they will be cascaded to replace, and as far as I can see there simply isn’t. Unless of course an export market develops, and I simply can’t see that taking off for EMUs.
Things only make sense if there’s a mass amount of electrification due to come on stream within about 5 years, and whilst this boat did at one point look like it was about to sail, it’s now firmly back in the port.
Things are even more crazy if demand does tail off in the next few years , which it does seem we are seeing some indications that could at least be a possibility.
Perhaps the undesired class 700s could be exported and replaced with 12-car ex Southeastern Electrostars? Now they have a nice interior which matches even the much-loved 365s!