Gladiator: Aristotelian Tragedy.

I chose the movie Gladiator to supplement Aristotle's idea of Tragedy and or Epic in his essay Poetics.

Here is a rough summary of the movie, for those who have not seen it or are unfamilure:

Maximus is a powerful Roman general, loved by the people and the aging Emperor, Marcus Aurelius. Before his death, the Emperor chooses Maximus to be his heir over his own son, Commodus, and a power struggle leaves Maximus and his family condemned to death. The powerful general is unable to save his family, and his loss of will allows him to get captured and put into the Gladiator games until he dies. The only desire that fuels him now is the chance to rise to the top so that he will be able to look into the eyes of the man who will feel his revenge.
http://www.imdb.com/title/tt0172495/

“A tragedy, then is the imitation of an action that is serious and also, as having magnitude, complete in itself; in language with pleasurable accessories, each kind brought in separately in the parts of the work; in a dramatic, not in a narrative form; with incident arousing pity and fear, wherewith to accomplish its catharsis of such emotion" (230).
I believe that the movie touches on all aspects of what Aristotle believes Tragedy is, however it is important to point out that there are 2 main differences between a Tragedy and an Epic: time and narration. Where a Tragedy is usually told within the span of a day, an epic has an unset or unlimited amount of time. The story of Maximus in the movie spans much longer than a day, yet I would till categorize it as a Tragedy.
This brings me to the second difference which is that an Epic is told in narrative form or from an omniscient narrator, while a Tragedy is more of a dialogue, which is more like the movie.
I want to explore why some elements of Epics can be found in Tragedy but not vice versa.
Additionally I want to explore why Character seems to come secondary to Plot when it is the Character the viewer or reader identifies with and is the cause of evoking pity or fear in the audience(236).
Lastly, since it pertains to the movie Gladiator, I wanted to discuss the demise of the Hero and why with an authentic tragedy must the death of the Hero always be the product of some fatal choice or action, for the tragic hero must always bear at least some responsibility for his own doom, when in the case of Maximus, it was not his choice.
Is this only reason of why the Hero dies found in poetry, or because we live in a time with so many variations of what a Tragedy and Epic could be in viewable formats instead of literature, has there been an evolution of Aristotle's Poetics?