Perhaps you are forgetting the first 2 games mrazek played against the caps. He plays very well against them and should have played. The team plays better in front of mrazek and a big reason for that is because of his ability to handle the puck and they just have more confidence in him (in the shootout as well). So yes the team probably would have gotten more shots on net.
I don't care how well Howard played, he didn't win. He has an ability to find ways to not win. He gets paid 5 million dollars to leave his legs wide open in the shootout every single time. Maybe he should practice that while mrazek starts to get more starts.
Getting a win is a team thing, it's not solely the goaltender's fault. Howard allowed 2 goals, that should be enough to win most games in this league. Both our goalies are playing well, Mrazek has faced far more shots on average and as a result has a worse GAA overall. Mrazek is certainly the future but he and Howard are on par with each other at this point in time, at least the way I see it.