Is it much? Maybe more like 14mil but its not impossible.
Well with 10m sold just announced looks like Switch will be around 12-13m by end of 2017.
Predictions (Made July 2019)
LTD: PS4 - 130m, Switch - 110m, XBO - 52m 2019 : PS4 - 15m, Switch - 18.8m, XBO - 4.8m 2020: Switch - 22m (Peak Year)