Also, as they went along, Syrio never used her name. At the last training session, when she made a mistake -- in not seeing what was truly happening -- he called her "dead girl" repeatedly.
Jaqen H'ghar met Arya when she was disguised as a boy -- and he called her Boy. But it was clear that he always knew. And he never calls her by name. She is just "a girl" and eventually "no one".
And although many people in GoT have various accents, Syrio and Jaqen have, I think, the most unique manner of speaking. It's not the same between the two, both both talk unlike anyone else.
I don't know what the books will do, but I think the show will link the two.
Good episode tonight. But I have to say that, on the whole, I find the Unsullied to be not very impressive. Grey Worm notwithstanding.