IMH Opinion, I would first replace the rear springs.
Our 126 was an "ass sitter". I replaced the rear springs and was delighted with the difference it made. No squat under accelertion and no looking up to the front passengers from the rear seat.
I decided not to change the front springs but instead just used thinner spring pads all around. I then I got it re-aligned.
Keep in mind that Mercedes measures correct ride height by suspension arm angles.
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)