The typography in Android P looks strange now with the addition of Product Sans alongside Roboto. The old graphic design rule of "never pair multiple sans serif

The typography in Android P looks strange now with the addition of Product Sans alongside Roboto. The old graphic design rule of "never pair multiple sans serifs" is hardly absolute – different sans families can often be successfully paired as header and body, for example – but in this case, there are headings rendered in Product Sans with barely-smaller subheads in Roboto, which just looks jarring.