I already do this for another team of writers, so I am quite understanding of the unique language and culture barriers in the article writing process. I am a Native English speaker/writer who was the editor of both my high school and college newspapers.
I can work a few hours per day, but would need a better understanding of what this work is, how often it needs to be done, and what I can do to help you make the best quality articles you need.
I actually work with one other editor, so we are a team, and while I bid for myself, if you require bulk work, we are quick, good, and reliable. Please see PMB for details.