I can't speak to the '09 Chargers, but I can state categorically that neither of the Dallas teams you mentioned could hold a candle to the Harbaugh era Niners.
2007 Dallas was by far the best team Romo has played on, but it was also an aging team (especially on the OL). They lost in the divisional round to the Giants because they committed 11 penalties to NY's 3, and because of several critical drops that cost them scoring opportunities.
The 2009 Boys did manage to win a playoff game (the only playoff win for this one proud franchise since the end of the 96 season), but then went on to get the hell kicked out of them 34-3 by the Vikings on the road: 6 (!) sacks allowed, -3 in turnovers. The Vikings DL just completely overwhelmed the Boys un-athletic OL, and that was all she wrote.