They were all kept in their place, although they were different sorts of places, and we must beware of falling too much for modern social-engineering critiques.
The officer class could sometimes get away with a great deal of nonchalance, or apparent nonchalance, about professional training. But much more even than in the present day, they were expected to be what I believe Richard Holmes called "almost incomprehensibly brave". The young officer who portrayed excessive concern for his health in moments of crisis bore the mark of Cain outside the army as well as in.
The "Sharpe" TV series was in one respect inaccurate. In the Napoleonic Wars it wasn't uncommon for officers to be promoted from the ranks, and for the most part well received in their new ranks. Complex stratagems to help the most popular pay their peacetime mess bills and expenses weren't uncommon, and there were cases of officers marrying sergeants' widows. Transfer to the Indian Army, where an officer could live on his pay, was always available. The officer corps was always far less the preserve of the aristocracy than many people believe, younger sons of minor landed gentry, who also struggled with expenses, being far more common. Anyway, in my very limited acquaintance with the aristocracy, they are far more likely to have personal friends among what used to be called the lower classes, than yuppies are.
Social exclusivity probably reached its peak in early Victorian times. But by the time of Rorke's Drift in 1879, nobody doubted that Colour-Sergeant Bourne, who is in contrast to the movie was a bright young man of 24, would have made lieutenant-colonel without the battle. In the First World War no wartime-enlisted or territorial officer rose to command a British division. But Sir William Robertson, Chief of the Imperial General Staff, a peacetime major-general and Commandant of the Staff College, had held every rank in the army from cavalry trooper. He had, however, been a regular trooper, which made all the difference.
Of course the only other officer I know to have served in every rank in his army was Marshal Bazaine, who did jail time and died in poverty after a commuted death sentence for the Franco-Prussian botch-up.