That's a fair point. I have no real problem with Hodge playing Carter, but more the "well Egypt is in Africa so why not" logic because it marginalizes other people who live in an area and don't conform to the majority demographic.
I would have preferred an Egyptian actor if we are racebending Carter but, again, I've liked Aldis Hodge in what little I've seen him in and am sure he'll be a great Carter, likely the best live action incarnation since I'm not crazy on the few times he's showed up in other adaptions.
They can get around her if the flashback is set after her death but before Khufu's, assuming they don't have to die together. Or they just don't meet and save that for his solo if he gets one.