Spoiler: The Winter Soldier is actually

Bucky Barnes.

WARNING: This individual is named in the answers below. For now, let us call him "the subject".

Assuming that the subject is simply a normal, superpower-less, human soldier, why would Captain America's enemies, Hydra, waste time converting him into the "Winter Soldier", especially as he is/was severely injured and not a natural supporter of their regime (hence having to brainwash him)?

Would it not have been easier to simply recruit from within their own ranks (those of Hydra) and find somebody much more willing and aligned with their cause?

The subject does not possess Cap's super power(s) and is brainwashed, so, presumedly, he can't remember anything that might be useful against Shield/America/Captain America?

So why bother with him???