He took 613 face offs and won 51.9% of them, for 318 wins. Eichel won 47%, Larsson 50.7%, Rodrigues 46.4%, Mittelstadt 40.2%, and Johansson is 41.8% on his career (he barely took any last year). Even if we were to assume Mittelstadt, the worst of the bunch, takes every face-off Vlad would take (and the total number of faceoffs is roughly equal), you're only looking at 68 fewer faceoff wins over the course of the season. Less than 1 per game! And we know Mitts won't take all of those faceoffs, and it's possible he got better at them. It's simply not a big deal.