Was not Egypt of the time (1100-1300) still a majority Christian nation.
I t had a large Coptic population, although I don't know just how many they were in contrst to the Muslims. But theoretically, they might be natural allies of the Latin Crusaders, that is, if they're willing to use accept their help in the administration role. Apparently, even during the Fatimid Era, their were alot of Coptics serving in bureaucratic roles.