I think what's there is enough, when you consider the time and money that goes into printing sourcebooks, when you consider the amount of research required for a
good martial arts supplement, and when you consider just what a niche it is in Shadowrun. Take a look at the HERO games "Ultimate Martial Artist," and you'll see a book that covers a lot of martial arts very well, but that obviously took a whooooole lot of time to put together. They did it because "Ninja HERO" has been a popular genre of their generic rules system for a long time, because martial artists are a popular schtick in a Champions (superhero) genre that also uses their same rules, etc, etc...
But if you look at how many other ways there are to fight someone in Shadowrun, and you look at what a niche-within-a-niche melee combat is, and then dedicated martial artists within
that niche...the pay off just isn't there. There's already a pretty big chunk of
Arsenal dedicated to martial arts, and that's more than enough for the
vast majority of campaigns out there.
Folks that know the difference between Pekiti Tersia Kali and Guro Dan Inosanto's Kali are few and far between...and, really, the difference
in an RPG is negligible. It's enough for both of them to be lumped in with all the other Kali/Escrima/FMA arts, and just given a few cool bonuses with the appropriate weapons. You can describe your awesome footwork and masterful stabbing however you want to, once you sling the dice and do well in an attack.
Likewise, with the eight hundred billion styles of Kung Fu. What does it matter -- in your average Shadowrun game -- if someone's using Choy Li Fut versus Wing Chun? If he's making an attack roll, beating his opponent by a whole lot, and doing X amount of damage...guess what?
Describe it how you want to.
You're free to add all the detail you want in your home games, just like folks can describe their HK 227 as a 9mm, or their Ares Alpha as a .223, or their Ares Predator as a .40,
if they want to. There's no need for extra sourcebooks to use company resources and time, to delve into additional detail that (a) might be wrong, which will freak people out (just look at the clip vs. magazine argument), or (b) could be time spent working on something else.
Right now, my only beef with the martial arts rules (as per
Arsenal) is that they come from Qualities points. That's a steep, steep, cost, and I'd like them better if they were linked somehow to your Unarmed Combat skill, came out of skill points, etc. On the one hand, I like that you can make a Kimbo Slice or a Bob Sapp (by having a mediocre Unarmed Combat die pool, but just crazy points spent on +1 to DV so that if you land a solid hit someone's head comes off)...but I think the chapter and the rules would just
flow better, feel more cohesive, and be more fairly priced if they were linked to skills more directly.
That's house rule territory, though, and not something that I think
needs a rewrite.
(As a side note, I heard about a fighting monk over in China studying boxing because it developed very impressive hand speed.)
A vaguely popular guy a few of us may have heard of,
Bruce Lee, did the same thing. He incorporated quite a bit from American Boxing, and even some Fencing, into Jeet.