I can't tell if these are running in parallel or not. It looks like cylinders 1 and 3 feed one of the turbos while cyls 2 and 4 feed the other. That doesn't really make much sense to me.

Subaru used to sell a twin-turbo Legacy a few years ago, but that's a flat-4 with two banks of cylinders so it makes somewhat more sense.

Now, running two turbos sequentially (a la the Mazda RX7) could give a flatter powerband but only up to a certain point. Generally once you get into the really high output areas running more than one turbo per bank of cylinders becomes too unpredictable.