Why Fassbender in both roles?
Why is Callum physically identical to his Spanish ancestor? Are we supposed to accept that the genetic lottery somehow made two "twins" separated by a couple of centuries? Or maybe the modern day Callum is a clone of Aguilar?
I hope the movie has a good explanation for this and not just some *beep* about Callum "visualizing" himself as Aguilar just so they can maximize Fassbenders screen time.