If the worry is about the manufacturer rather than the design, then we have more than two data points. The Soyuz-2 launch vehicle, which is replacing Soyuz-FG,

If the worry is about the manufacturer rather than the design, then we have more than two data points. The Soyuz-2 launch vehicle, which is replacing Soyuz-FG, has about a 10% failure rate (including an ISS resupply mission in 2015). This was as far as I know the second-to-last -FG flight planned, as manufacturing has been discontinued and the -2 is the main production line now.