I think those were from fan productions... everything else is accurate.
And of course Voyager is faster, it's smaller. That doesn't translate to great combat ability though.
Except that Voyager was launched roughly 7 years after the Enterprise-D.
Starfleet was building smaller and more powerful ships ever since the BoBW - the Defiant is a prime example, and Voyager could easily be as well.
Just because a ship is smaller, doesn't mean it cannot match or surpass the larger ones in terms of combat ability.
The Enterprise-D has to support a much larger crew, ergo, its life-support (which is a power hog anyway you put it) would draw that much more power compared to the one on Voyager.
Also... the galaxy class has a number of different non-combat systems which are left on during combat situations.
Voyager is a stripped down star-ship if anything - minimum amenities... think a compressed Galaxy class.
Also, while Voyager is able to reach much higher Warp velocities... that could be easily due to more efficient ways of achieving Warp in the first place (variable nacelle geometry) which wouldn't necessarily require more power.
Btw... since when are small ships inherently faster than bigger ones?
The Defiant was rather slow if anything and the crew had to go out of their way to increase the speed to levels (without shaking itself apart) where the Intrepid for example would run circles around it (and probably the Galaxy class).
The approach to the Defiant was to completely remove ALL crew amenities.
Given the size of the ship, its no surprise either.
The Intrepid on the other hand is 15 decks large (about 11 decks more than the Defiant).
While the Intrepid would employ far fewer amenities compared to the Galaxy class, if it was built with the similar philosophy in mind like the Defiant, then it would be able to match a Galaxy class in combat situation.
The torpedo counts between both ships is a different story.
Its probable the Galaxy class has an inherently larger storage capacity given its size... but the Intrepid would NOT be limited to mere 36 photons (because the Defiant was left with 45 after a large combat), and rather the number could be in well over 100 range.
The Galaxy class would have more torpedoes to spare, but I doubt either ships shields would hold on until they expended 100 of them each (actually both would collapse probably when reaching the number 10, maybe 15 or so).