I'm comparing the first mirror universe story to the first NuUniverse story. Later stories can take a different spin on things, let's compare the first with the first.
And who's to say that Vic wasn't based on someone in DS9?
If you're comparing "Mirror, Mirror" to STXI, you've got to include the prequel, "In a Mirror, Darkly". In that the NX-01 crew breaks up, the ship is destroyed, the USS Defiant from the prime future is aquired, Archer's killed and it ends with Hoshi declaring herself Empress. Also, the Empire is very much in force (with multi-species crews) years before the Federation or Coalition, there are at least nine NX-class ships in the 2150's. Even ignoring all the deviations prior to this episode (an Empire flag is planted on the moon in the 1960's, Shakespeare etc) it's not believable that 100 years later history will be an exact mirror for the prime universe. That the ISS Enterprise looks as it does when they had the Defiant is bewildering enough.