I doubt Vengeance is that much more powerful than Enterprise for its context compared to Narada (i.e., Vengeance is far closer to Enterprise than it is Narada). Twice as big or so will equate to more room for a larger reactor/more reactors (twice as powerful in the least), which will mean more power to propulsion, weapons and warp; in addition to greater stores and magazines. Enterprise was a new vessel too, a new heavy cruiser. Vengeance can be seen as a new dreadnought analogue, with more than likely cutting-edge weaponry and propulsion -- cutting-edge for present day Starfleet, not from where Narada came from.
Say, instead of 2 torpedoes from Narada, it'll take 4 or more to hull Vengeance; Narada can put out that easily enough. Whereas Narada is going to soak up whatever Vengeance can throw at her. This being as Enterprise soaked it up for several moments without catastrophic damage (if it were away from stellar bodies, there'd be no worry for unplanned reentry).