Chronicles of Narnia might not be a traditional setting for a real-time strategy game, but that hasn't stopped someone from using it as a setting for a Total War mod.
Titled Narnia Total War, the total conversion brings CS Lewis's iconic world into Rome: Total War. It's from the creator of the original Warhammer: Total War mod (back when modders had to shoehorn Games Workshop into the Total War themselves) and has a total of 14 playable factions, including Lone Islanders, Dwarfs, Archenlanders, Narnians, Harfang and a ton more.
It's a mod for the original Rome: Total War, so the Narnians aren't the prettiest lot.
There's a series of quests to let you reenact key moments from the books, as well as customised menus, loading screens, icons and the whole shebang to sell the whole appeal. It'll still take a bit of imagination on your part, since this is the original Rome: Total War, but it's a massive conversion nonetheless.
It makes me wonder what a proper Chronicles of Narnia strategy game would look like, with a small team and a reasonable budget. Aslan would certainly fit the bill as a Total War giant beast, commanding from the front lines.