If we parse it the way teh government usually parks things, it does not say ”aircraft with similar performance and handling characteristics” (in this case). I interpret “Model family” to be aircraft of similar design, ie “all RV tail draggers” or “all Sonex tail draggers. Elsewhere in the APP program, it does talk about “similar aircraft”, and there my interpretation is different - if it flies much the same, then it is similar.
Just my personal interpretation!