I don;'t know where you get performers from. It was one guy in a character suit running in from a side door with a flashlight, who jumped around to synched dialog and ran out. There were 4 stunt performers in T2. And if you want to be nitpicking, Captain EO had synched in=theater effects before MV.
T2 was, at the time, one of the most advanced shows in an indoor theater. MV was no where near as complex. Just programing the hydraulic lifts itself was a nightmare - and that had to synch with film, sets, etc. One of my friends worked on the programming for T2 and the fact that it looked so seamless and non-revolutionary belies the fact it was, in fact, incredibly complex. Also they had to transition from live action/film to film, back to live action/film. (Most people never even noticed that the host stand actually sank down into the stage and was covered by a platform).
And the film itself was, at the time, a complex marvel - no only running in 3D but was actually enhanced to look sharper (Cameron is a noted 3D fanatic). At the time it was, per minute, the most expensive movie ever produced.