We can walk between rail vehicles (in the form of the passenger cars) without hitting E to do a transition. Perhaps this improvement could be put into the CSX locomotives (oh, and maybe even the autoracks!) to make crossing between them faster? Hitting E and then the crossover animation isn't exactly a totally smooth motion.
It wouldn't be a totally smooth motion IRL either unless the crossings were down between locomotives permanently. Passengers vehicles work because the corridor connections are already in place. Of course if TSW ever models older passenger stock then that will not be the case.
