why? just look at the total war series. it's a seperate mini-game in itself. it's supposed to be fun and challenging. hopefully they will fix it in this game.
Ummm...the diplomacy in most of the Total Wars reeked. In my opinion, that is. It mainly bought you some breathing room from time to time. Which is, I agree, much better than Sins, but that doesn't really say much, now is it?

And second, Total War is not a RTS, not in any shape or form. It's a TBS with RTS battles. That's entirely different.
You want to see an example of a RTS that done it exactly right? Seven Kingdoms 1 and Seven Kingdoms 2. Granted, they are old and wrinkly now, and their graphics could make your eyes bleed, but no RTS ever beat them from diplomacy stand point. Alliances, surrenders, spies, bribes, demands for attack, demands for defense (which surprisingly worked - the AI actually came to your defense! That never really happens in RTSs, at most they just say they're coming but won't budge. In 7K your ally's army was right next to you on the fight and requested), you could convince one AI to attack the other, you could even offer the AI to purchase its entire kingomd and annex his empire to yourself. And if you were large and strong enough, and had a lot of money, this actually worked!
Ahhh, sweet reminisces

This really was an amazing game, mind you. Very much ahead of its time. Too bad almost no one played it.