She as mother Group

My small team has more writing work than we can handle right now. We tried splitting it between ourselves, but the work keeps getting pushed back because everyone has other tasks. I started looking into an online copywriting agency as another option. I have never worked with an agency before, so I am curious about how communication usually works. Do you speak directly with the writer? How many changes can you normally request? If anyone has tried this, I would really like to hear your experience.