The numbers in the OP show just how much of an uphill climb the Switch has in replacing two systems. Yes, the Wii U did modest numbers but when you place that total on top of the successful 3DS, that's an imposing goal.
That total hardware units sold will contract is a very likely outcome, perhaps even by a significant degree.
I hope we can get some good software numbers (including digital) so we can find out if the Switch is selling a lot more software than either the Wii U or 3DS did on their own, which it has to do in order to be considered a success.