I hate to throw a spanner in your works, Epitome, but how to pen an action sequence is something pro's and amateur writers alike still argue over today.
As film is a visual medium, I'd advise that you write what is seen.
Avoid technical stuff (Japanese names for aikido take-downs), and do not over-write. If you have a Fight Choreographer attached to the project, he'll likely burn your text anyway - it's his/her JOB to stage the best scraps of everyone's ability.
That said, ONLY if advised by a producer (provided you're writing on assignment) should ever pen the uninspiring, THEY FIGHT.
Sigh, I remember reading that in a version of Sleeping Tiger, Hidden Dragon and thinking, "WTF is THAT sh1t about?!"
On a final note: if you could track down the screenplay for Lethal Weapon, you'll read a brilliantly simple, yet concise final fight.
Oh, and the Bourne fighting system was designed by the Fight Choreographer, and none of the locks, rolling around MMA style crap was included in any drafts I've read.
