A problem for China, Korea and Japan names is that by default in R:TW, the surname follows the firstname. In these nations the family name proceeds the surname. E.g: Takeda Shingen son of Takeda Nobutora.

I don't know if any factions in Rome had the family name before the firstname or if this can be scripted in, but it is somewhat of a problem when it comes to making the correct feel. I suppose you could just put the firstnames instead of surnames and vice-versa but then there would be children not being named as the son of their father.

Just a potential problem for your consideration.

For Japanese family names, you could add a little Total War retro feel:
Oda
Chosokabe
Mori
Takeda
Shimazu
Hojo
Uesegi
Imagawa
Others:
Fujimoto
Hashimoto
Kawamura
Nakashima
Ôshima
Satô
Takahashi
Ueda
Watanabe
Yamaguchi
Yamamoto

Male names:
Akira
Eiji
Gorô
Hideki
Hideo
Hiroshi
Hitoshi
Ichirô
Jirô
Kazuhiro
Kazuo
Ken'ichi
Kenji
Kiyoshi
Koichi
Makoto
Masao
Masashi
Masaso
Masayoshi
Minoru
Noboru
Nobu
Ryôichi
Ryôsuke
Seiji
Shunsuke
Takashi
Takeshi
Tasô
Tetsuo
Toshio
Tsutomu
Yasuo
Yôji
Yoshi
Yoshihisa
Yoshio

Female Names:
Akiko
Atsuko
Emiko
Fumiko
Hanako
Haruko
Junko
Kaoru
Kazuko
Miyuki
Michiko
Toshiko
Yuriko