Hallmark is using Lionel's blueprints for a train Lionel made
for 0-27 gauge years ago, that is why nothing matches prototype
dimensions. Remember Hallmark is recreating in minature toys
from under the tree from ages past. Lionel was infamous for using
stock passenger cars and just re-painting them.
On the bright side in 1976 Lionel made a H.O. Scale American Freedom
Train that came with a FA-1( Non Prototypical) low priced set or the
higher priced set with the GS-4 Daylight steam loco.
I have the complete set of it.
A few years back Hallmark came out with the Lionel GS-4 in SP Daylight
colors, then the year late a 2 inch mini ornament came out.
I'm tempted to send my H.O. Scale Freedom Train set to Hallmark
Design Studio's so the get the hint!