The reasons I believe it to be true is information from Col Elting's information on the Russian Army which is taken from L'Armee Russe sous le Tsar Alexander I, de 1805-1815 by Marcel Gayda and Andre Krijitsky, as well as Wilon's book on the campaigns of 1806-1807 and the material on the Russian artillery contained in the Zhmodikovs' two volume work.
The Russians were artillery heavy-being that their divisions had as much artillery attached as a French corps and their brigades as much as a French division. Their biggest artillery success was the destruction of Augereau's corps at Eylau in 1807 when they had three large batteries concentrated in their center. One note Col Elting made in the Atlas regarding the artillery duel at the beginning of Eylau was that the mere weight of the bombardment caused heavy casualties in Soult's IV Corps.
Russian gunnery, skill, and leadership among the officers was poor. That is directly related to education and training and the Cadet Corps responsible for that was stripped of artillery-particular education/training at the beginning of the period when they Cadet Corps were reorganized. This was changed and updated later, but the damage had been done and the Russians did not catch up officer wise during the period. Substitution quantity for quality has always been a Russian trait (for lack of a better work). Peter the Great did it against the Swedes, it was done by Alexander I during the Napoleonic period, and the Russians did it during both Wars I and II. And the technological side of the technical arms has more-than-often been behind that of the west. Artillery-wise in the 20th century it definitely has been and undoubtedly still is.
The French artillery arm performed much better than that of the Russians in 1807, 1807, 1812, and in 1813 with a rebuilt and largely raw artillery arm. At Friedland in 1807 the Russian batteries across the Alle were silenced by French artillery while Senarmont destroyed the Russian center. At Borodino in 1812 the French artillery dominated the battlefield. The only noteworthy artillery success the Russians had was Eylau, and they didn't win the battle.
The Russians until at least after 1807 still practised counterbattery fire as a main doctrinal tenet. Further, they were never capable, doctrinally or command and control-wise, of employing their artillery as the French did, though some Russian artillerymen, as well as such commanders as Barclay de Tolly, certainly advocated it. Along with this the gunnery practices which are directly related to officer training and education as well as realistic training during peacetime, were inferior to that of the French-and that is not myth, contrary to some beliefs or ideas.