About the only thing I do not know is why all the horse power far a transfer unit?
A transfer job hauls cars between yards within a terminal, or out to interchange points. It’s considered yard work, but you can have quite a large cut of cars on one of these transfer jobs. You better not get some wheezy old goat on a transfer it they expect you to pull tonnage. And a transfer job from track side can look like any main track road job…all the cars; all the tonnage; all the power. (you hope!)
To get over the road at a reasonable speed. The “transfer unit” is an adaptation of the dual engined E-unit for freight service. Slightly behind its time. If Baldwin had come out with the DT-6-6-2000 in 1940 they’d have sold hundreds of them.
The reason for all the horsepower on those Baldwins, or any other transfer loco, is because locos in transfer service handled long cuts of cars, and in some cases, had to carry them a ways to an interchange or switching yard.