For what it's worth concerning alignment control draft gear; they became NECESSARY back in the 1960s with the introduction of higher capacity (extended range) dynamic brakes. During heavy use of dynamic braking on steep down grades, the alignment control draft gears keep the couplers from swinging too far to one side in the locomotive's coupler pockets, and trying to derail the first car behind the power consist.
Steam locomotives did NOT, and do NOT, have dynamic braking, so the alignment control draft gear is not needed. However, that being said, all the big class one railroads have developed "policies" over the last 10 years or so, of NOT transporting ANY type of locomotive, IN A TRAIN, that does NOT have alignment control draft gear. Thus switchers, "F" units, and various other "old historic" diesel units must now be loaded on flat cars in order to be moved by the railroads.
