I’d say you’re doing quite well. 38 is a good number. Those top ten are very very difficult to achieve, really out of reach if you don’t play 14 hours a day for almost everyone.
I will say re grip, if your car has better balance it has more grip.
For example if you are late braking very hard and try to turn with the car standing on its nose you won’t be able to take turns as fast as if the car was more level.
4 tires have more grip than just two.
Also you get more grip by not loading the tire all at once, a smoother build up of forces helps sometimes.
Realize 2 seconds or 3 to bottom of top ten is way beyond average