In 1854 you could buy a commission to quickly raise rank. This would mean only rich families would become officers, and not because of military knowledge/mulct, as officers would need a private income. Sources 4+5 seem to disagree with the view that Lord Cardigan was a national hero, in fact they oppose it and infer that he was severely disliked by his en and the public.
Source 6, a book called “forgotten heroes”, says that Cardigan IS a hero. He is known for leading the Charge of the Light Brigade at the battle of Balaclava. Source 4 is written by Captain Eager. The source is a primary source, a letter to his wife. Captain Eager had served under Lord Cardigan from the start of the war. He says In his letter that “If self-importance or bluster are necessary for command, then he Is the man” referring to Lord Cardigan.
He also says he gallantly went to the Russian guns, but left the brigade to get back the best It could. The source therefore infers that Lord Cardigan was an Incompetent leader, Captain Eager did not Like him and that Cardigan abandoned his men to their fate at the battle of Balaclava. This letter is reliable as its to his wife, a private letter not meant for the public, so it is the truth of events, It is still useful as it’s point of view from the soldier, although it was written 2 months after the charge.