That's not possible since distributions from traditional and Roth accounts require different codes in box 7; a distribution from the Roth 401(k) account will include code B in box 7 and a distribution from a traditional 401(k) account will not.
[Edit: See my follow-up reply below. The single Form 1099-R is correct.]
Sometimes a payer will include multiple Forms 1099-R as separate lines on a single page. Vanguard seems to be one of these, so check to see if this page is actually two Forms 1099-R. Otherwise, contact Vanguard for an explanation or a corrected Forms 1099-R.
