I do not understand the angst of Wennberg going 5 for 11 on the dot against Tavares - one faceoff the other way and Wennberg would have been 54.5% against one of the top 5 C's in the league. Too small a sample size to take anything from. Your text sounds as if Wennberg was expected to dominate the dot against C's who are admittedly more experienced and with extremely high talent level.
Having said that, I do understand some of your concern as against Toews - 3/13 is abysmal. Hopefully a one-night schooling. But it would not take much for Wennberg to get there. All-world C's who achieve 55%+ on the dot means the opposing C's will average 45%. Wennberg needs to get to elite level on the dot, and it will take a little more time. 7/13 would be 53.8%.
A little eyebrow raised after Saturday, Ok sure, but I am not particularly perplexed over FO% based on 2 games.