Do experienced legal secretaries cost law departments the same amounts as midlevel paralegals?

According to Robert Half Legal’s summary in Met. Corp. Counsel, Vol. 14, Dec. 2006 at 56, law departments should expect to pay for “midlevel paralegals with 4-6 years of experience” salaries in the range of $45,250 to $58,000. Departments should expect to pay “senior executive legal secretaries with seven or more years of experience” in the range of $46,500 to $60,500.

That means a paralegal and a legal secretary with roughly the same number of years of experience earn on average close to the same salary. I would have thought secretaries lag behind paralegals, but perhaps “executive” legal secretary implies more skills and higher pay.