Yeah. To become a D1 you need to be an M2 who successfully manages (ideally) more than one other M2, who themselves might manage M2s or M1s or a combo. So you get really large chains of people at the same level in a reporting line, all managing and trying to show that they should be D1s.
It's actually amazing to see empire builders in action. While some EMs are busy trying to keep their teams on track, others are rolling entire teams under them and growing their mandate