The idea is to try and get lots of creatures on the board and then overload weapon surge or dynacharge on them. I took Xanzure's deck from http://www.mtgtop8.com/event?e=5161&d=229765 and after 20 games or so, replaced the Krenko's Commands with Ash Zealots.

I have lost the last 10 games on a trot with this.

I feel partly it is because I am a new player, and have no idea what I am doing when trying to decide mulliganing and sideboarding decisions (part of why I chose this deck is I thought it would make those decisions easier).

Is this deck just rubbish? Does it have no chance of winning in today's meta? How should I mulligan? How should I sideboard? Please advise!