GM is just infatuated with re-using model names. The Blazer and Jimmy names were already doubly used once the S-10 based (GMT330) SUVs came out in 1982. The Blazer name continued on the 2-door IFS SUV from 1992-1994. After that, the miniature one was the only Blazer. The full-size Jimmy disappeared after 1991, and only sort-of re-appeared as the Yukon, so all Jimmy's were all miniature after '91. To make it more confusing, the "Trailblazer" and "Envoy" appeared as packages on the S-10 based SUVs before they were models of their own (GMT360) in 2002.
As if having the "real" (i.e. squarebody) Blazer/Jimmy be identical wasn't enough, the smaller one could be badged Blazer, Jimmy, Bravada, Trailblazer, Envoy, Xtreme or ZR2.