I find it odd how they have depowered the Asgardians, atleast physically. In the first Thor we saw Volstagg casualty lift a car to help a little girl look under it, yet here we are seeing physical struggle against ordinary humans. Loki took a beating from the Hulk in the Avengers that would have killed a human too.
I figure it is an inconsistency for the plot, otherwise the Asgardians might just be too dang strong. There would be little reason for them to sneak onto the train, they could have just taken it.