I just skimmed through the German Sandman by Hoffman and its wiki entry and noticed some interesting stuff. Don't qoute me exactly, but take a look and be your own judge.
This is what quickly jumped out at me along with a few minor cross references.
Coppelius was a Lawyer. -Lucius allows access to the special forces unit which the Lawyer model is a part of.
While working with Coppelius, Nathanniel's father takes on a pained countenance which twists his features to look like those of Coppelius. -Those in association take on a similar appearance??
During the slaying of Nathanniel's father he refers to Coppelius as a devil, specifically, and in some interpretations of the story Coppelius is viewed as a source of great evil, all evil, or the evil that lurks in all men. - Much closer to our society's interpretation of the Devil then the western, dream spreading, Sandman. And two common names for that concept are Satan and Lucifer. Im sure you can see the similarity between the mytholgic name and the character name.
Later in the story Coppelius takes on the form of a different man. -Ability to change his appearance. Penchant for deception. Ever hear of that Lord of Lies title???
In the Rising Powers rule book, read the last paragraph of the Lawyers description, specifically the part about how they all sign a contract, yet never reveal to whom. -Definitely an allusion to the infernal.
Now Im not saying that they are all one and the same, Im just noting the few things that came to my attention rather quickly. The only thing you can put me on record for being 100% sure of is - I don't think that parallels of this frequency are solely coincidental. There is some connection between these characters besides what has already been stated.
That being said, the soap box is there for whoever wants it next.