Miller isn’t close to the back that Kamara WAS. But he doesn’t have to be. He just has to be close to what Kamara will be over the next few seasons. That seems possible because Kamara doesn’t have a positive trend.
Thing is, that's not a true Alvin Kamara replacement. What tweaked people about NWsaints statement was that you could put Miller in a Kamara jersey and people wouldn't know the difference.
What AK brought to the table as a dynamic route runner and receiver while also being a good running back is what Miller has shown zero ability to replace.