I'm currently reading Bernard Cornwell's Sharpe novels, and they make it seem like significant numbers of the British officers at the time were dilettantes. Cornwell quotes statistics like only 1 in 20 officers being promoted from the field, while the rest bought their commissions using their own money.
Generals clearly would have preferred experienced officers with a good knowledge of strategy and tactics, did they train their officers or have any influence over who advanced besides offering field promotion?
Please bear in mind that Cornwell is a novelist and is trying to create an atmosphere in which his "working class hero" can be seen to be particularly successful. A dilettante officer wouldn't last long on active service in the field, so although they existed, they weren't as significant as Cornwell would have us believe. Many officers did buy their initial commissions, but there were promotions from the ranks, and many were promoted, once commissioned, on merit. John Shipp, for example, was promoted from the ranks twice. First in 1805, a field commission. He sold his commission in 1808, and subsequently rejoined the army as a trooper in the 24th Light Dragoons, and was again given a commission in 1815. Artillery officers were very well trained at the Royal Artillery school at Woolwich.