Interesting, I usually do a big chunk of braking for Wehrseifen in the straight, coast through the right-hander leading in (or even tap the gas), then do the rest of my braking in the miniature straight leading into the hard left. Judging by your image, that's not the best way to do it. Perhaps I should try saving my braking until later; I've preferred the way I do it because braking through the right-hand turn can upset the car.
This depends on tuning setup. However, there's nothing wrong with your approach, in my opinion. The only point I'm making is that it probably feels like
MrYasser is losing too much time under braking; this is something I used to feel in Forza 2 and 3, even before GT5 came out. Therefore, I remember reducing the brake pressure on my Skyline GT-R R34 in Forza 2, and slowly learning to trail brake there.
Indeed, you're correct, some cars have a natural tendency towards oversteer. If you find that your car has even a touch more oversteer than you'd like, your line is actually the preferred line of many drivers, including, as far as I'm aware, Sabine Schmitz.
However, as I normally drive FF or AWD cars with a heavier front brake bias, I find the trailbraking line to be the most efficient means of navigating the corner, given the increase in rotation offered by trailbraking in an FF/4WD car. This is something I learned in autocross, actually, with my Hyundai Accent; steering while braking puts a lot of weight (and grip) on the front tires, while making the rear end a bit more loose than you expect.
So, TL;DR it's a question of which car you're driving. Porsche/RUFs/BMWs will take a 2-phase braking line, while FF and 4WD cars will take a trail-braking approach, for the increased rotation. That same rotation that spins some FR/MR/RR cars can be very useful in the fight against understeer in some more understeer prone cars.
Edit: In fact, I've found this video...
The MINI Cooper S you see at 5:25-7:20 in the video is trailbraking.