A more probable context for a Rashi - de Bouillon meeting would be political alliance and protection of the Troyes Jewish community. But what could Rashi offer? Perhaps information. Much of the so-called Crusades were exercises in selective cultural destruction. It is estimated that some twelve thousand Jews were either murdered or committed suicide rather than submit to a forced conversion to Christianity. Hundreds of scholars were martyred, holy books destroyed, and a generation of Jewish learning lost. By 1096, Rashi had certainly amassed many rare manuscripts as part of his later consolidation into a single accessible volume. Due to his intellect, years of study, and access to ancient texts, Rashi undoubtably knew more about the Holy Land than any Christian scholar of his day. This fact was probably not lost on de Bouillon or other key nobles of Champagne and Lorraine. What would be more natural than to consult the leading expert of the day? Insuring his protection would also make good strategic sense, especially given political tensions between regional duchies and the erratic King Philippe I.
Of additional significance, Rashi could translate Hebrew into medieval French. In his writings, Rashi refers to French as "our language" or as the "language of these people." Since Hebrew was not then widely taught to the Jewish population (and certainly not commonly understood among Christians), Rashi thus played an important translator role.
It is thus reasonable to assume that de Bouillon, a duke sympathetic (according to contemporary accounts) to religious scholars, may have been willing to offer physicial protection to the Jews of Troyes and duchy of Champagne in exchange for Rashi's useful information about the environs of Jerusalem. One historical fact is that Rashi's vast consolidation of ancient source materials did somehow survive. Had it not, hundreds of years of work by thousands of earlier Jewish scholars would have been lost forever. Rashi's life's work and the curious way it flourished during this dark period was not just a scholar's forture, it was crucial to the entire continuation of Jewish existence at that time. A second historical fact is that Godfroi de Bouillon proved to be amazingly successful in launching his Crusade in the Holy Land. His military intelligence, from whatever source, proved decisive.