hmmm.. well, I practice Leung Ting Wing Tsun and Escrima Concepts. both are self defense systems... first thing we were taught in WT was our "universal solution" for self defense situations, that is pretty much what the whole first WT grade is about anyhow. After that it just goes on getting more advanced and being more offensive I guess. It all is of course very much based on being a practical and useable self defense system.
now the escrima concepts is mostly about sticks and "other weapons" (palmsticks, fists, knives, bottles, pens, shoes, or anything). It is, like the WT system, concept based and has a very solid thinking behind it and is very workable and aims at keeping yourself safe at all time. in Escrima concept we always presume that an opponents hand that we can't see is a hand he carries a weapon in and we have to act accordingly. Taking control of the situation and the opponent with some appropriate technique.
the "basic" disarm is of course to whack someone in the head with a hickory stick
trying grabs and things is very tricky with people who know how weapons work =( we are taught disarms for emergency use if we ever get jumped by some fool who doesn't know how to use his weapon of choise but we are also taught the basic truth about disarms ("they don't f..king work")
WT and EC is all about control and keeping yourself as safe as possible, and are very self defense orientated systems.
it is interesting to hear that your "circle of self defense" starts at brown belt jovial! =D we start doing that after maybe a week or two of WT training! We have something similar in EC too, one guy is charged buy 3 or 4 stick/knife carrying attackers. very good training , makes you think of how to react !