Oh, you mean like Kivas Fajo, the guy who kidnapped Data because he wanted the most toys?It would be the equivalent of having a script about an alien species whose culture embodies stereotypes about Jews, and then casting all Jewish actors to play the part.
Well, I haven't seen "The Most Toys" in years and can't say if I think it's anti-Semitic. But we only saw one member of that species; we didn't see every single one of them being played by Jewish actors.
It would be more akin to having only Jewish actors play Ferengi... while wearing yarmulkes.