This intro does kind of make me feel like the Sovereigns are somewhat weaker in the game than they are in the intro. In the game they're just a hybrid of a pioneer and a hero, as we've stripped them from all the special stuff they had in WoM.
Interesting Observation! ... Can't really say that I would argue with it either. However, on balance, I still like the Intro video very much. There are at least two reasons why I'm happy with the "flavor" that it conveys.
The first ... is simply that I am happy to give the Intro story-teller (and animators) the benefit of the doubt. I think they have some legitimate "Poetic License". We can forgive them for playing up the drama and the atmosphere, and don't need to expect them to exactly convey the specifics of the gameplay. On one level, this is kind of like an advertisement; and we all know the differences between say, an advertisement for a nice car, and the reality/costs/limitations of owning the nice car.
Secondly, I think an over-arching issue of Gameplay variety and balance, differentiates FE from WoM. One thing I really love about FE, is that you can productively use Outposts, in lieu of settlements, and thereby avoid the need for city-spamming that is an inherent (and tiresome!) feature of Civ 4. You don't have to play as a micro-managing administrator. On the other hand, I do like some aspects of the 4X world that Civ 4 represents; and I find that my personal gameplay style tends in that direction.
I don't tend to play as if my Sovereign and Heros are standalone figures (lonesome wanderers). Nor do I care much to spend a lot of time using them as Empire Administrators. ( I prefer to use them as Ceasar figures, rather than Augustas figures. ) I tend to play them as military leaders in charge of small armies. One of the beauties of FE (IMHO) is that you can play them any of those three ways (Heros, Administrators, or military squad-leaders), or in a number of other ways. There is much more variety and balance in FE (and breadth and depth too), than there was in WoM. As a result, it doesn't bother me that the sheer power of the Sovereign and Heros (at least at the beginning of the game) is reduced, from what it was in WoM. If they start out weaker, I'm basically okay with that. Of course, this is just one person's opinion ...
... and I may change my mind (and my gameplay style) next week! 
Happily, I am confident that FE will allow me do just that.
