I didn't believe it either, but the Battle AI in both Napoleon and Empire is unthinkably inept. Even with Darthmod, you'll see the AI do something remarkably stupid in combat every other battle or so. Mainly the AI doesn't really know how to defend while mixing fortifications, artillery, counter-flanking, artillery and counter-artillery. In between adding those features after Medieval II, it looks like they never really spent the time training the AI how to use them.
Also, naval battles are terribly tedious affairs that you'll grow to hate. Since the whole point of the game is to go global, lots of naval "action" is unavoidable. You'll either have two trains of battleships chuggling around each other in circles, or fast outgunned ships running away while hardly any shots are fired. The novelty of it wears off fast.
Honestly, your best bet is to stick with Medieval II or Rome. Or, assuming your rig can handle it, you could spring for Shogun 2, which made battles interesting again by copying Victory Locations from Neocore's King Arthur series. Shogun 2 has a minor expansion pack coming soon, and as a general rule of business, games go on sale the week their expansions come out. Shogun 2 also should be good preparation for when Rome 2 comes out next Fall.