15.6% only refers to VW branded cars. VW group cars (VW, Audi, Skoda, Cupra,...) have ~30% total market share.

Kinda surprised Tesla hasn't split into multiple brands for high end, mid range and cheapo cars.

That way they can sell cheap shitty cars without damaging their reputation for high end vehicles.

The idea that this is a good idea is very questionable. If you buy an expensive car, you expense quality. If you buy a cheap Tesla you get a cheaper product. Not sure why costumers wouldn't be able to understand that.

The many brands are mostly historical by consolidation in the industry.

Yeah, it's a bit confusing with all those brands. Tesla is just Tesla, but Volkswagen is a company and also a brand, and the company owns the brands Volkswagen, Škoda, Seat, Cupra, Audi, Lamborghini, Bentley and Porsche. But it is owned partly by another company called Porsche as well.

So yes, Tesla sold more cars in Germany than the Volkswagen brand, but fewer than the Volkswagen group.

The interesting part here is how close Tesla is in VW group home market and how far VW Group is away from them in the US/China.

This is essentially due to different marketing decisions by VW. VW, like most car companies, has loads of brands. Tesla has one. Items 2, 6, 12, 13, and 21 on your list are all VW. VW could, if it wanted to move up on that leaderboard, rename the Cupra (Seat sub-brand) Born, which is a mildly weird-looking id.3, id.3 (mildly weird looking trim) tomorrow.