Do MU connections these days include a CAN line or 2 for bidirectional control? If this thing is to run as a true hybrid, it needs to be able to control what the connected diesels do as well as providing power itself - spool the engines down when the battery unit can carry the load, such as in yards or other slow-speed operation, regardless of power setting in the cab. Think of it like a Prius: engine operation is based on power demand, not "throttle" setting, and power demand is modulated by what's available from the electric side. So while there may be a default setting that would work with any diesel, it would work best with mated and modified diesels that have additional firmware.

At first, this beast sounds crazy, but on further thought, I like the idea.