Restricting Google to Dutch language results shows 454.000 results for "hugo de groot" site:nl and 45.000 for "hugo grotius" site:nl. In English, the results are 568,000 for hugo grotius and 310,000 for hugo de groot. An interesting linguistic anomaly and likely indicative of the status of Latin as a lingua franca.

Still, those who argue against putting their nation first can hardly in good faith argue for putting their national idioms first. Perhaps the Dutch, so as to not be accused of unseemly nationalism and ethnocentrism, should adopt the internationally-accepted Latinisation? After all, it's hardly without precedent.