>>1991939Locomotive pulled trains only make sense for:
1. Night trains, where it is common to mix/match/shunt trains midway to allow more connectivity and traffic is not speed sensitive.
2. When you need to run longer trains on non-electrified territory. Larger diesel engines are cheaper to maintain and operate than an equivalent power in smaller ones.
3. You run really, really long trains - like India-level 10-15 car ones, and you already have a bunch of wagons to do it.
Also - the flexibility of loco-hauled trains is grossly overstated. Firstly - it is rarely needed. Secondly - with a fleet of EMUs of varying lengths ( pic rel - PESA elf series can be had from 2 to 6 section versions ) you can respond to traffic changes just as well and day-to-day savings from running EMU will overwhelm benefits of this mythical 'flexibility'. There is a reason why MU took over. People who run passenger trains are not dumb.