As I was preparing to begin a new AAR recently, my first in a while, I spent some time thinking about the merits of each game as far as AAR writing, as well as in general. I'd like to share some of those thoughts now, and get some other ideas and feedback as well.
Firstly, as a disclaimer, I only own 4 TW games: Medieval II, Rome II, and Warhammer I & II. Medieval II was my first total war game ever, and I didn't get it right after release either, so basically the result was that by the time I had finally played it enough to consider looking for another total war game, the most recent title was Napoleon, and I am not particularly interested in that time period as far as gaming goes (though it is historically fascinating). I purchased Rome II when it came out, was unimpressed and so I didn't buy Attila (or play R2 for a while, for that matter) though after the patches I recently picked it up again and got some good play time out of it. Then, like any good fantasy nerd, I purchased both Warhammer titles, which I have thoroughly enjoyed playing. I consider myself a mediocre player overall, though I am decent when it comes to Med2, but I don't think skill discrepancy really played a role in this experience.
My first thought, since I have recently been playing Warhammer, was to write a Warhammer AAR. However, I discovered that my desire to actually write about the game I was enjoying was rather minimal. I came to the conclusion that between Warhammer and Medieval II, CA turned the game itself into a more narrative experience. This means that it has more replayability between the different factions being completely different experiences, and the different quest battles etc being woven together to form a story-based game (particularly with the introduction of the WH2 Vortex campaign.) This can make for a massively enjoyable actual gameplay experience for someone who is only approaching the game to play and try to beat it. However, because the game has a story by itself, writing about it seems to have less value to me, and trying to go back and replay a faction seems less enticing as well, since there's such a streamlined story already being told.
Then I considered writing a Rome II AAR, because why not? Like I said, I have been enjoying the game more recently, and an AAR seemed like it would possibly be a good way to connect with it. The actual game systems are in many ways improved from Medieval II, presenting more of a challenge and allowing for different regions to develop differently. Choices must be made when it comes to what buildings will be constructed, and this adds replay value for the same faction, and even more between different factions. However, I couldn't really generate any connection to the characters, especially since they could just be plucked out of thin air to command my armies, and the trait system feels a little tired and repetitive before long. I will say that from my limited experience the new politics patch has fixed many of these issues. In fact, in many ways I still think Rome II can make for a good AAR, in fact, there are several fantastic Rome II AARs on the forum right now. For my personal preference however, the game systems get in the way of storytelling.
So finally, I was back to old, reliable (modded) Medieval II. Unlike WH, and to a lesser extent even Rome II, it does not have much replay value on the surface, even between different factions. Someone playing the game purely to play the game is going to wind up doing the same thing over and over, the only thing that might change is start position and unit colors/models, but at the end of the day, all the cities are going to be totally upgraded, and all the armies are going to be elite, heavy-cav centric with some infantry to hold a line and archers and artillery to tear to poor, unsuspecting ai apart. However, this belies the true value of going back to the game over and over, because someone who isn't interested in the game only to beat it, but to tell a story will find more ways in Medieval II to make the story their own. Varied general traits, different self-imposed playstyles and limitations seem more possible. The more simplistic settlement system means that a migration-style campaign won't be punished or rendered impossible. Because not every army needs a general, and generals don't spike the upkeep costs so severely, characters can be more than just commanders, they can stay back to govern settlements, or they can lead a specialized cavalry strike force for home defense without it being a massive resource drain.
Of course, the thing everyone will point to is the family tree which ultimately makes Medieval II so rewarding for storytelling purposes, and this is true, but I think there's a lot more to it than that. In some ways, as gameplay is improved and expanded on, it becomes harder to find a story to tell between the threads of what is happening (or at least for me, since even for Medieval II I tend to ignore actual game mechanics and reasons to focus on my own, and the more of these mechanics there are, the more I have to ignore). To an even greater extent, as the game itself becomes a story, as we saw with Warhammer, it becomes even more difficult to find your own story to tell about the game. These are just the very rough sketch of the thoughts I initially had when considering my options. I'd love to hear what other people think.