As much as I agree that overcrowding is a problem on the route, where could sufficient 3 car units be released from without causing overcrowding elsewhere? Would a half hourly service, even if some were 2 car sets, alleviate the overcrowding somewhat?
Agreed - it does all seem to finish a bit early east of Leicester.
Sounds like a solution looking for a problem. Neither GA nor TPE have traincrew at Nottingham, which is where - inevitably - the majority of traincrew for the route are needed.
If it has to be 170s they'd have to come from Scotrail, however it may be possible to swap the /5s with the /6s at London Midland in a few years, after chase line electrification, or if LM again the LO 172s.
If other 3 coach trains would be appropriate, it may be possible to swap the 27 170s for 25 185s from TPE, but only if the chiltern cascade doesn't go ahead.
A third option could be swapping the 170s with the 175s, which although would leave two coach units they'd be 2 more 3 coach units and if wales needed a replacement for the 2 lost coaches a 158 from SWT shouldn't be too hard to make available.
The final option would be 27 of the 159s, while this would leave a micro fleet in the south, SWT also have 158s which are very simular so shouldn't cause any problems. It'd also cause a shortage of stock in the south, but they don't seem to be very strechted with DMUs at SWT and can often loan DMUs out elsewhere, so may not cause too much overcrowding. I'm also not sure about how much the 10MPH lower top speed would be an issue, as I don't really know the line east of Leicester.
The above is all based on the service staying hourly east of Leicester, but especially if the 185 option is chosen, it should be possible to increase it to half hourly following further electrification.