Most of Figaro's English speaking population seems to get along. I see no harm in aiming for the same server across the board. It'd probably be good to get the word out now for maximum exposure.

We can probably assume most DE/FR players will go to server 10.
Likewise, the nature of 8 being a lucky number in the eastern cultures makes it inevitable it will attract such a population, much like how 3 and 7 are more lucky in the west.

Yeah, 6 sounds good.