The ~77 VW Scirocco (sp?) is the first modern car I know of with a single front wiper. That predates the W201 by ~15 years. The second gen Jag XJ sedans also had a single front wiper. Why some XKEs have 3 front wipers is the next question.
To be sure, the MB design clears a lot more of the windshield with it's bobbing motion.
I find the W108/109/114/115 wipers to be more effective than the W116/126/R107 wipers.