Your British Troops in this are "The 24th"?
After careful thought, and remembering that I had a really great granddaddy in the 24th Foot at Rorke's Drift during the Zulu Wars, I decided to check to see if the 24th were around during the Peninsular War.
In fact, they were. In 1804, Second Battalion was raised and after having seen service in the Peninsular War, Disbanded and joined the First Battalion, which the vast majority of the First was captured at sea by the French in 1810. in 1814, they were deployed to Nepal, were they fought in the "Gurkha War" Were mutual respect was gained.
The 24th saw service in North America, Peninsula, Nepal, India, and eventually Africa, before they were renamed to the South Wales Borderers during the 1800s. Today, They are now known as The Royal Regiment of Wales.
Sorry for the History lesson, I got carried away.
Good luck on this modification!