re: #498 Leonidas Hoplite

He also turned the military conventions of the day upside down and was able to use that against his opponents who didn’t change their thinking until after getting their collective asses kicked - several times

Yep - but then, as always, Hybris struck.
It wasn’t just the Russian Campaing, although that was a quite spectacular end.
Before that, Napoleon’s armies were well and truly trounced in the Iberian Peninsula by none other than Wellington, who got the measure of his beloved Marshals there.
Thats how and why Wellington was able, in the end (and with a little help from the Prussians under Bluecher) to defeat him once and for all.