Adye certainly had data from European artillery in his publication. Further, foreign artillery only became 'important' to the French as they captured it and the great numbers could not have been that important, depending on the year, because quite a few captured field pieces were melted down at least once to create a monument to the Grande Armee in Paris. The allies were quite generous in giving the French the opportunity to capture so much ordnance, especially the Austrians who left the Vienna arsenal intact twice, in 1805 and 1809, for the French to take and employ.
As to the Gribeauval System and the 'information' that has been presented from time to time on various forums, too much of it is inaccurate and presented without much detailed research. That is unfortunate because the system was excellent and entailed much more than field pieces and ancillary vehicles.