Doesn't sound familiar to me. It could be a stock music cue. (There music clip wasn't very long, so it's hard to tell.) Hopefully someone else will be able to shed some light on this. :unsure:
The trailer is well made! will def. watch this movie :)

And indeed its clash of arms by XRD
You can't, it was written by a company whose sole purpose is writing music for trailers like these. They are sold for a considerable amount of money to movie companies to use in adverstisements.
Re: Alexander the Great

Hi everyone, who knows the song used here? It doesn't sound like clash of arms by x-ray-dog.