When you say multiple gear reduction t-case systems do you mean that there are other gear sets for a transfer case?
No, I am referring to multiple gear reductions as in dual or even triple gear reduction transfer case systems, ie. "The Marlin Crawler Dual Case"
The beauty of the Toyota gear drive transfer case is that it's gear reduction portion may be stacked upon one another thus doubling or even tripling the number of gear reductions in the drive train.