Vikings Defence

Hey guys. I bought your Madden e-books, the offensive and defensive guides.
The offensive guide has really up'd my game. The defensive guide seems good too, except that I use the Vikings, and just recently I was told how crappy they are in Madden 12 as a defence.

Reason why I use them is cuz I love to run the ball, I average 138 rushing YPG, plus i'm a huge Vikings fan. But my issue is not scoring, its trying to stop those assholes from always coming back to beat me. I cant stop the deep ball with the Vikings if my life depended on it. 3 defenders on Calvin Johnson, and he still leaps and makes the catch. And my players don't intercept anything.

So my question is, is there a Vikings depth chart out there where I can shift around players on my defence so that they are at least competitive?
Or
Do I switch teams and use the Ravens?

What would you all suggest???

Thanks,
Paul