This is a time management question. Most auditors will have multiple clients at once. This is especially true if you're working for an audit firm like PwC or Deloitte. You have to be able to show when you're working for one client and not the other for billing as well as for explanations why something has been paused. Clients don't like to hear or know about your other clients, but most are understanding.
Take me, for example. I work full time at a tech company, but when I'm home and have down time, that doesn't affect my current job of assisting with these postings. I also have a blog that I write. It's all about time management.