The sources that tell you to have a one-page resume typically expect you to edit out anything that doesn't apply to the job you are currently applying for. It

The sources that tell you to have a one-page resume typically expect you to edit out anything that doesn't apply to the job you are currently applying for. It makes some sense. You're trying to ensure that all the high points in your resume get read by making the reader's job easier. At the same time, re-writing your resume every time you apply to a new job is a tremendous burden, and simply impossible if you want a consulting agency to keep it on file.