Selecting a spot to defend against Napoleon's onslaught was vital should Wellington wish to be successful. If he stationed his team behind hills...perhaps garrisoned on the reverse slope...then...when Napoleon's cannon barrage were unleashed...some might die...but...most would survive due to the trajectory of the cannon balls when firing against hills.
Of course...everyone knows that Wellington simply waited for the cannonade to end...then...arrayed his team to slaughter the on-coming French.
“Everyone knows their own army best; but if I were to fight here I should expect to be beat” ~ Duke of Wellington
Had Napoleon stayed in Paris and not ventured out to attack the combined forces of 6 nations...however...he would have sustained his "come-back" for at least a decade. The natural defenses of the region surrounding Paris would have enabled this military genius to capitalize on the inability of the anti-Napoleon team to remain united long enough to eradicate him and his army of 500,000.
While President Trump does not fancy himself another Napoleon...Islamic State leader Al-Baghdadi does. And it's this arrogance that enabled Big Don to marshal his troops and chase ISIS out of Iraq and Syria. So successful has been President Trump that military experts are studying his concept* of robot-drone warfare.
*Trump explained the idea simply by noting equipment can be replaced...people can't be. He would dispatch robot-drone regiments to wipe out any enemy in less time than it would take to organize and deploy the same number of "real soldiers".