Very clear and simple to play cheap'ish deck. Wouldn't buy the Planeswalker. No point in purchasing a card to never draw it in a game. Particularly on a budget.

agreed Loreshadow... I would splash red to play crackling doom to get rid of fat eldrazi and siege rhinos and add 2 bloodsoaked

I've found that Ajani Steadfast does wonders in B/W warriors, more so even then Sorin. While that could just be a personal experience bias, I think as far as planeswalkers go, he is a considerable addition. Also, it should be noted that planeswalkers are a great flavor for warrior decks acting as the leaders of a battalion of warriors. Really cool deck to build, and your own build is pretty nice!