If you would be dumping the cards at the studio, it would be easy.
You’d just have a raid5 and data tape backup done every night automatically.
No manual copying after dumping at all.
Problem is in the field, you need electricity for that raid5 box.
But usually there is electricity available and you could set up laptop and storagebox right where you use to have a film loading tent. And clapper/loader can handle copying like s/he has handled film loading before.
Copying can be done simultaneosly with shooting, loader just has to verify that it happened properly.