You did not reply to the fact that Romo had the benefit of a good defense so I will assume you concur.
However, when it came to the running game, their contribution wasn't limited to the playoff games. Felix was just as responsible for the team's late season rally as any other player.
In the last four games of the 2009 season Felix averaged 5 yards a carry as the Cowboys went 3-1. Felix averaged 5 yards a carry in the Viking playoff game.
There was no point in the 2nd half where the game was still close, they we're down by 14 at the half. Felix started the 2nd half with consecutive carries of 16 and 9 yards. He averaged 7 yards a carry in the 3rd. The 4th quarter was garbage time, they were down by 17 and then by 24, then by 31as they constantly attempted to pass.
As for the Eagle playoff game, the first score was aided by a defensive pass interference for 40 yards, another drive started at the Eagle 18 yard line due to the defense recovering a fumble, another TD drive before the end of the half started in Eagle territory due to yet another fumble recovery.
Romo didn't blow the game open, the great defense that Romo supposedly never had did it.