Turn around is also solved with a special car that has a driver cockpit for remote control of the locomotive on the other end. But some high speed trains like the Velaro (also running in Spain) don't even have locomotives anymore, they just have cockpits at each end of a multi-car segment, and all the motors, transformers and so on are distributed along the whole length of the train.
I think that GP meant with "Skip the engine all together, and make trains fully dynamic" would be something where every single car could be autonomous and they just connect together (on the go?) for slipstream and traffic control. This is both real (segments are joined primarily for traffic control, "cars" already have their own motors etc) as it is far away (the individual cars of a segment are joined together at the factory and form a single articulated unit)
I think that GP meant with "Skip the engine all together, and make trains fully dynamic" would be something where every single car could be autonomous and they just connect together (on the go?) for slipstream and traffic control. This is both real (segments are joined primarily for traffic control, "cars" already have their own motors etc) as it is far away (the individual cars of a segment are joined together at the factory and form a single articulated unit)