Here's some material from Rosen's paper on Gribeauval that might be of assistance:
‘Gribeauval was hailed as the great mind who had discovered the true principles on which to found the constitution of the artillery.’ Rosen, 13 citing DeScheel, 132.
Frederick the Great, whom Gribeauval had met, described him as ‘One of the great military engineers of the time.’ Rosen, 13, citing the memoires of Frederick the Great, 277.
DuTeil mentioned in his Usage, i, that Gribeauval ‘rendered the artillery more scientific.’
‘The Systeme Gribeauval was as perfect a work as is humanly possible.’ Roquerol, L’artillerie au debut des Guerres de la Revolution, 249.
During Gribeauval’s tenure with the Austrians in the Seven Years’ War it was said that ‘…Gribeauval was able to exert considerable influence over the Austrian artillery.’ Rosen, 21, citing Hennebert’s work on Gribeauval, 27.
Prussian General Tauenzein, who commanded at the siege of Schweidnitz until Frederick took over referred to Gribeauval as ‘that devil Gribeauval’ for his skill against the Prussians during the siege. Rosen, 23.
‘…the systeme Gribeauval was a genuine system, a thoroughly integrated blend of organizational principles, tactical ideas, and technology. Gribeauval conceived of the artillery as a system in which each part was designed in functional relation to the whole.’ Rosen, 30.
‘…’every aspect of the systeme Gribeauval was designed to achieve a specific purpose: to create an artillery force with sufficient mobility to participate actively in offensive field operations.’ Rosen, 30-31.
‘…the systeme Gribeauval embodied a thorough commitment to the concepts of mobility and utility.’ Rosen, 31.
Perhaps this will assist in your understanding of the period. Just for clarification, there was no M1792 or any other 'M' systems in France during the period. There were improvements and modifications to Gribeauval's work, just as there are modifications to modern systems and weapons, such as tanks and artillery pieces. However, they are still known by their original designations with the modification noted, such as M1A1 for a newer version of the M1 Abrams tank. There were four artillery systems used in France and by the French from 1732-1829 with the introduction of the Vallee artillery system: the Valliere System, the Gribeauval System, and the Systeme AN XI. And AN XI can be considered a modification of the Gribeauval System as it developed from it and was not a radical departure from it.