Well if Yamato is a SH, then maybe she was planned as well as one of the ten members.
Ace was probably planned as well.
I already own all the English Volumes.
But if they ever released the colored volumes in print I would just recollect them.
It would be stupid in todays climate and a show dedicated to the Western audience to make all the SH's Japanese. I think a multicultural cast would help the series alot and help the series gain traction and bring in fans. As I don't think Oda ever cared about the SHs being Asian in the first place.