I watched Sharpe's Rifles and there seems to be a disdain for Sharpe amongst the soldiers of the 95th Rifles as Sharpe was a soldier promoted to an officer, why would this be and how common was this in the British army during the Napoleonic wars?
The more usual way for an officer to rise in ranks would in those days be through literally buying his commission. u/GeneralLeeBlount explains in this thread, also asking about Sharpe. It also examines how they'd look at the men, and therefore, Sharpe. It must be noted that this system was not universal throughout the entire British Army at the time; u/Bacarruda and u/Andy_R00 comment on non-purchased commissions here.
I highly recommend picking up the books the TV movies are based on. The films are rather low-budget and really suffer in depicting the larger battles Sharpe finds himself in. Bernard Cornwell, the original author, still 'Hollywoodises' the actions Sharpe finds himself in, but he does include a historical note as to what he's done that was counter to reality.