How does this negate the efficiency from slack? Each bogie is sized to move one car and all the cars move independently. Isn’t that effectively slack? Unlike re

How does this negate the efficiency from slack? Each bogie is sized to move one car and all the cars move independently. Isn’t that effectively slack? Unlike regular freight trains, it wouldn’t have the momentum of all cars in front helping to start any given car, but on the other hand, that momentum was still produced by the locomotive earlier in the starting of the train.