It seems to me that the medrashim praising the Jews for their use of Jewish names should make one wonder what constitutes a Jewish name and why the use of Jewish names is praiseworthy; among the Biblical generations the concept seems less obvious than it is for us. Perhaps a name is Jewish because it makes it's bearer recognizable as a Jew, or because it expresses a Jewish worldview (such as by praising G-d). Perhaps this is praiseworthy because of some practical consequence of these qualities: discouraging assimilation, making Jews feel the weight of our other praiseworthy (or disgraceful) behavior, or simply helping Jews find one another. It seems to me that the name Theodor might "read" as Jewish because of Hertzl, and that a somewhat corresponding Hebrew name like Nassaniel/Nathaniel (which, like Theodor, means "G-d has given") would do so even more strongly.

It seems to me that the medrashim praising the Jews for their use of Jewish names should make one wonder what constitutes a Jewish name and why the use of Jewish names is praiseworthy; among the Biblical generations the concept seems less obvious than it is for us. 

Perhaps a name is Jewish because it makes it's bearer recognizable as a Jew, or because it expresses a Jewish worldview (such as by praising G-d). Perhaps this is praiseworthy because of some practical consequence of these qualities: discouraging assimilation, making Jews feel the weight of our other praiseworthy (or disgraceful) behavior, or simply helping Jews find one another. 

It seems to me that the name Theodor might "read" as Jewish because of Hertzl, and that a somewhat corresponding Hebrew name like Nassaniel/Nathaniel (which, like Theodor, means "G-d has given") would do so even more strongly. (Other possible references to Hertzl would include Binyomin Ze'ev, Hertzl's Hebrew name, which rosends suggested; and Hershel or Hirsh, perhaps related to Hertzl in etymology.)