Time
How can we convince administration to add an assistant to increase our time management?
I agree, with having to explain why the instructor would need an assistant. Time management can be hard at times, but as an instructor, you are in control of your time. Don't overload your plate. It's okay to say know. It's better to say no than to fall through on your obligation when you said yes.
I think it would be helpful if we manage to get two or three instructors requesting the assistant. This could be incorporated into the request AFTER discussing the reasons the Instructors feel they need help.