1) Becke neglected to provide an indication of any primary source for "evidence" of the exchange attributed to Napoleon that you referenced. I only discovered parallel sources by accident. Doesn't make Becke, as a source, very useful with regard to being primary, does it.
2) The Napoleon-quote appears to me completely immaterial with regard to indicating that SÚnarmont developed a new artillery doctrine at Friedland that was then recognized and implemented when possible or useful thereafter by French artillerists. In fact, Napoleon's jocular recognition of gunners' hotheadedness seems (to me) to reflect familiarity with what SÚnarmont was doing - something already within the tool-box taken farther than customary.
3) Generally, Becke's sourcing of information used is miserable. Nice bibliography, but at a glance, I'd suggest that a significant portion of his essay is lifted directly, and without attribution, from other sources - in the 19th century tradition of simply making use of good stuff already available. So not only is it hard to discern what is primary material with regard to the Napoleonic period, but it is hard to know just what is Becke's and what is someone else's work.
Sincerely - Howie