Actually, we have a great example of monk orders developing into a non-asian setting in the D&D multiverse: the Githzerai.
While they were enslaved by the Illithid, they probably weren't allowed weapons of any kind, and through the centuries of psychic abuse, they developed unparalleled spiritual and physical hardiness. I suppose the unarmed fighting styles must have come over the course of the centuries since then, but they certainly would have helped in the revolt of Gith and Zerthimon.
In fact, unless I'm much mistaken, it's under similar circumstances that Capoeira came to be in our world; from what I understand, it was hidden under the appearance of dance and rhythm, and since the slaves had their hands tied, they learned to rely on kicks and lower-body movements for their martial art.