Depends on your skill level if you can change engine mounts, I like to raise the engine with a hoist as opposed to a floor jack/block of wood on the sump. Components like engine mounts I go OEM, they are too bothersome to replace if they fail.

You can't really guess which component is most llikely to cause the vibration.
Inspection of the rubber on the mounts is the first step, and since they are hydraulic check to see if there is seepage.

HAVE YOU CHECKED THE RUBBER ON YOU ENGINE CRANKSHAFT HARMONIC BALANCER ?

I think an experienced mechanic can look and have a good idea from visually checking if a mount is bad.
Hopefully a mercedes tech on this forum can guide you better then me.