So what is really different between french& german

[Eric Swanson]

One of my former teachers put it well by saying that "A good German player is better than a poor French player, and vice versa."

I know some folks who play both and use them in different situations, German for solo, French for orchestra, or vice versa.

I have only used French, having started on 'cello, and frankly, am not that good with that, these days...

I have always heard what Ken said, that it has a lot to do with how one's hand and arm fall at one's side, naturally, and what teachers are available.

I would talk it over with your teacher. I find that teachers who can talk meaningfully about this are those who are making a living with the bow (read: professional orchestral players) or someone who has worked and trained in that world.