1) Lack of emotional impact upon Bucky's demise, needed more set-up.
2) Not enough passage of time was conveyed with the montage.
I'd have tried solving both of those by removing the Howling Commandoes scenes which were themselves so limited as to be near pointless. They could still have appeared in a few scenes, but as nameless background characters to be expanded upon in a later film. Here, they're just eating up screentime better spent elsewhere imo.
Take out the HC, add more Bucky, and either extend the montage or have two, one focusing on Cap vs Hydra, and the other depicting the passing of time and Steve's involvment in other areas of the war.
Originally Posted by Bruce_Begins
and Nazis did not make an appearance.
Even with them on film (and in my personal favorite scene from the movie), this old chestnut refuses to go away. Good Lord.