Thrones of Brittaina does look very nice. However, checkers is a more widely known and played game, and some people just prefer checkers over chess. Shogun II and earlier Total Wars are chess, and later Total Wars, especialy Thronws of Brittaina, are checkers. If you are a very casual gamer, that likes their strategy very light, if a bit reptititve, then Thrones of Brittaina may be for you. more so than other historical periods using the same engine.
The navel combat in both the base game and expansions are more fun than other Total Wars (mostly), and the cannons and guns are really suited to the Warscape (modern) Total War engine. It also has one of the best expansions of any Total War, Fall of the Samurai. Mistakes were made, but it still plays very well even in 2018. It's the last game Creative Assembly made that still echos the better mechanics from the Golden Age of Total War, while still having a more modern interface, with timeless and stylized graphics. If you are a strategy gamer, the game you really want it is Shogun II, Total War. Unfortunately, Medieval II Total War UI feels very dated now, even to me, and as much as I love it I am often frustrated by it myself. Golden Age Total War games can be very deep and immersive.
Medieval II Total War is widely considered the last, best Total War from the "Golden Age" of Total War (the Golden Age defined by me as being the series of Total Wars from the orginal developers and also tend to use a better in-game battle engine that more accurately depicts physics of war, clipping, and has many little things that add immersion such as stylized ruler and general portraits, general speaches, involved and layered mechanics, and many little things such as your men carrying ladders to the walls, and so many other things just dropped for in later Total Wars).