Pretty much anyone who captured Bucky signed their death warrent in doing so. More often than not, he'd escape himself rather than waiting for Cap, and then he'd get a gun and kill some Nazis.
The whole idea that kid sidekicks are an 'indefensible idea' is just a silly one, regardless of the era. That was a solid genre convention up until the Eighties, and even then it took until the Nineties to really kill it at DC.