Random thought - Instead of modifying the GRP ID (and assuming you'd rather not be stuck with the GRN ID), the Gallic Junkers ID may suit your needs. You can roleplay them as intelligence collectors that are also privateers.
Additionally, your diplomacy then doesn't have to be so closely tied with the Gallic Crown
"You see what your knowledge tells you you're seeing. ... how, what you think the universe is, and how you react to that in everything you do, depends on what you know. And when that knowledge changes, for you, the universe changes. And that is as true for the whole of society as that is for the individual. We all are what we know, today. What we knew yesterday, was different; and so were we."
- James Burke, The Day the Universe Changed (1985)