Honda created Acura as a “brand” for the US market. They are not separate. Acura = Honda. Honda = Acura. In most cases (financial, etc) Acura doesn’t really exist and is not mentioned, as Honda is the company recognized by the rest of the world.
I would think the same is true of Infiniti, so the diagrams are slightly wrong. Just as Toyota has Lexus shown, they should have done the same for Acura and Infiniti.
As for Porsche, they own a 27% portion of VW. They were never acquired by VW. Porsche bought 15% or so back in the day to prevent a hostile foreign takeover of VW.
The chart is a couple years old. Maybe close to a decade. Definitely not 100% accurate for today.