Actually, I think your first explanation makes more sense--"in them" parallels "in the churches." (The gar is an explanation of why they should be silent, and the explanation using the word for "speak" rather than "prophesy" or "teach." So a command, then an explanation, another command, then another explanation.) This makes sense in the context. Paul is calling for order in prophesies (not restrciting them). Basically, stop interrupting each other. Go in turn so everyone can learn and be encouraged. Paul then specifically says in this situation, in this worship time in the churches, women shouldn't interrupt but should learn in a more fitting situation in their culture.

Another thing my friend talked about that I forgot to mention is the nature of Asian churches. He grew up in India, taught in seminaries in India for years, and now teaches in a seminary in Philippines. In Asian cultures, it was considered rude for people of the opposite gender to speak to each other in public places (i.e. church). Of course, it's not in our culture, so keeping in mind contextual theology, we need to be sensitive to that.

I'm still working all this out in my mind taking what my friend taught me and going back to the Greek (and back again and again and again). This dialogue helps me work through all this.