Some numbers there's logic, others no discernable logic.
I think the 201 number was used to denote a significant departure in strategy, given that the 201 was the "Baby Benz" and a totally new class of car that MB had not done before. It was a "stake in the ground" new chassis number for MB, considering that most everything on the passenger car side had done 1XX numbers since......forever.
Others more recently with the 200 chassis numbers were simply because MB had largely run out of 1XX numbers over the years, and to leave more runway for existing models (such as the follow-on 171 and 172 models and beyond for the SLK R170 series, for example).
Also, MB has in recent generations gone much more sequentially and rationalized things more logically than they had before ... 220, 221, 222, 223..... 210, 211, 212, 213......201, 202, 203, 204, 205.......
22X being S-class
21X being E-class
20X being C-class
Of course there are things like the 215/216 S-class coupes, the CLSs thrown in there, 208 C-class coupes, etc.
And then the Mack-daddy of all....the 463, which has been the same since......1990.
P.S. The thing I lament the most, is that MB is putting big round fat stars in the middle of the grills of nearly all of their models these days. It used to be reserved for the "sport" models like the Gullwing, Pagoda, 107, 126 coupe, and so forth. And G-wagens and trucks.
You had a star in your stock grill? You were driving a sporty/roadster/Mack-Daddy model. You were truly Sporty Spice.
Now practically everymodel has a nice round star in the grill, to go along with the AMG badgineering/displacement badgeflation.