As has essentially been said by Colovion, the battles are certainly a major highlight of the Total War games, but I find that if left to that alone I grow rather weary of the whole process. The battles, and correspondingly the game, have much more depth and a sense of purpose when in conjunction with the campaign mode. Taken alone you can find better battle simulation games, or better campaign style games, it's the merging of the two that makes the Total War games stand alone.