What I meant is maybe the tube end is bent such that the dipstick sits just a little higher than the spec oil level so it appears to read low. A possible check is to compare how much is extracted with how much is drained. The debate rages but many believe the difference is teaspoons. Your results might be different if use use the dipstick tube itself for extraction vs an inserted tube and the dipstick tube end is bent to be further from the bottom of the sump.

Maybe easier to send a vinyl tube into the dipstick tube to get a reading and compare with a trusted E320 reference.

After all this typing, is the dipstick tube pressed into the block all the way?

Sixto
98 E320s sedan and wagon
C320 wagon