Nope. Marvel still doesn't stand a chance. Because you did the only thing that ensures a DC victory. You put Flash on the team.
As long as there is no one of the other team who can match his speed and reflexes, the other team loses everytime.
Believe me, I want the Marvel team to win badly, but Flash makes that impossible. He could literally kill them all before any of them realized the others were dead.
I love Flash, just not against anyone who doesn't match his speed.
Now, if you threw Silver Surfer in there...then we'd have a fight on our hands.
But until then, Flash wins by himself.