I'm not sure about your model, but typically Mercedes springs are quite long and much more dangerous to compress than the spring on a strut or smaller springs on lighter cars. At least on older Mercedes, the only appropriate way was to use a plate style compressor with an internal shaft. Klann makes the correct one, and they can sometimes be found at low cost from ex-Chrysler techs.
Using an incorrect or insufficient compressor can have major safety ramifications.
At some point they moved to macpherson struts and then a broader range of compressors can be used.