Is Bucky Barnes in Capt. America Winter Soldier 'too tough or too old' for the character based from the Marvel Comics original version?

The original comic Bucky was Retconned a few years ago when the created the character of Winter Soldier.

In the comics, they revealed that Bucky wasn't cap's child sidekick, but a teenager spec ops commando. While Cap was running in the front of a Hydra base and drawing attention, Bucky was sneaking in the back, slitting throats, planting explosives and sniping the enemy. He was a ruthless boy, raised in the military and loaded with skills and potential.

He was found, fitted with the arm and frozen, only to be thawed out for a mission then frozen again, for decades. After he fought cap and regained his memories, he became a hero again. When Steve Rodgers was killed a few years ago, Buck took up the mantle of Captain America as a sign of honor. He didn't have the abilities or powers of Rodgers, but he had his own skills that he used well.

In one scene, he threw the shield at a group of terrorists and missed wildly. They all turned to watch the shield bounce around uselessly. While they were distracted, he pulled out his gun and shot them all. He quipped that he'd never be like Steve, but he'd do things his own way.

The movie mirrors the comics to a great degree. The Bucky Cap meet didn't not have any memories. He was only the Winter Soldier, a killer to be only thawed out when needed. That wiped his mind any time he started to show signs of returning to his normal self.

In the original story Bucky was a kid who became Cap's sidekick. In the "First Avenger" movie, Bucky is portrayed as an adult, roughly the same age as Cap, and someone who Steve Rogers intially looks up to. I suspect this was done because the idea of a kid going along on adventures with Cap in WWII would have been tough for modern audiences to swallow. If we look at other superhero films they've tended to eliminate the teenage sidekick aspect. For example, in Batman and Robin, the titular sidekick is played by an adult Christopher O'Donnell and not by the kid who he's supposed to be in the stories.

I think it is great they brought Buck Barnes back as the Winter Soldier as Captain America need someone a friend thet he knows and trust fully especially after the events of HYDRA in Captain America.

They borught him back also because of the possibility of CaptainA merica's death in Captain America 3 and Bucky will take over as Captain America.