It still seems like the methods should be -usable- in regular unarmed grappling, even if they aren't optimal. I dunno.
Well they (Aikido techniques) do pop up sometimes in unarmed situations, but rarely. The reason they pop up rarely is because of the set up.
It's important to train from the positions you are going to be in; what Tim Cartmell would call "the set up". It's hard to pull techniques out randomly and do them. You will most likely (in an "alive" situation) do techniques from the set up which you practice them. Further, some of Aikido's techniques can not be done from set ups other then we see in Aikido forms (shihonage for example).
In common unarmed fighting, the techniques are all done from unarmed clinches as the set up: bear hugs, headlocks, waist locks etc. However Aikido techniques are done from weapon clinches: Wrist grab, cross wrist grab, sleeve grab, lapel grab etc.
The focus of the confrontation in an armed fight is different then the focus of the fight in an unarmed fight. In an unarmed fight I can go right for the core, I can grab and control the core of your body. In an armed situation I must go for your core (center) via the weapon hand, or else I will be mortally wounded.
This focus on the weapon hand is what makes Aikido techniques "set ups" appear. With out the set up, it's hard to do the technique. Same reason many Bjj guys have a hard time going from gi to no gi, or judo guys from judo clinches to non gi clinches. When your set ups change so does your game.
Look, the principals of having something in your hand change very little depending on what it is. Size matters, and the way you use it. But if you can get your hand free, then you can use your weapon. You don't need to specialize in weapon retention for a 1000 different weapons. Aikido has methods for clearing small medium and large size weapons, that (in my experience) is enough.
I'm into training with aliveness myself(I don't like that word though) , check out our youtube page ( http://www.youtube.com/profile?user=ChuShinTani
), you'll see how we train, its pretty "alive". I had the theory I'm currently expressing for years, the idea came to me after I fought with the dog brothers, and it doesn't' get much more alive then that.
The techniques of Aikido never worked for me when I fought mma style fighting, or bjj. However they did work for me once I had a weapon in my hand. This theory is based on "alive" training, and not intellectual conjecture.
Here I am with anouther long post...