@RogerCooper I think the ahistorical presence of the Bolsheviks in Siberia makes the game more interesting and provides more options to both sides.
I haven't played against the AI in a long time. All I remember is that the AI is worse at handling naval stuff, not necessarily specific to the Americans on this map.
There used to be a tech that gave transports +2 movement, but it was nerfed to +1. Not sure if that would make any difference to the American AI's behavior.