This is an idea that has worked in other fiction. In ‘Gundam: The Origin’, Char Aznable and Casval Deikun were two separate (and similar-looking) soldiers in the Zeon army, but Casval took Char’s name as his own early in the war after a failed coup.
I recall that one early fan rewrite actually used this twist to some effectiveness. I would like to see another version of the story which includes this idea.