According to Tim Hall, whose Where Worlds Collide often showcases his Swiss modelling in N scale, a true crocodile must have the jackshaft drive and swiveling snouts.  Thus the Class D lacks the jackshafts, and the Pennsylvania's L5, which had jackshafts, lacks the swiveling snouts.

The "four-bogie" configuration (two pairs of powered trucks articulated with a span bolster, and notated B-B+B-B, was popular in North America until more powerful motors were developed.  Note that the North Shore alligator and the Class D have two trolley poles at each end.  These could be set up to run as two locomotives running in parallel, in which case each pole received half the current the locomotive drew in that configuration.  The Virginian built some very large freight motors (for North American readers, they looked a little like a Fairbanks-Morse cab diesel) with the B-B+B-B wheel arrangement.  The famous "veranda" turbines of Union Pacific also had that wheel arrangement, and they gave up their wheels and traction motors to go under the General Electric U50 double diesel, which paired two diesel-electric power plants under one hood.

Stephen Karlson ATTITUDE is a nine letter word. BOATSPEED.