At a second glance, what's the roofstalker dude in there for? It's slightly more difficult to play, but if you're pretty regularly getting both colors in, I'd use Tidehollow strix instead. It's a 2/1, always has flying, and has deathtouch, which can be enough to stop far stronger creatures from attacking.
Edit: added link http://magiccards.info/ala/en/203.html
Edit: added link http://magiccards.info/ala/en/203.html

