Yeah, it's all over the place. Clones are easy since they are all 6', TKs averaged 5'10" in the movies, TIE pilots were the same except for the two that flanked Vader in ANH, which were both reportedly women. Unless you have a short Vader or Wookiee, no one is going to get out the measuring tape, though if you are under 5'8" or so and build a TK, then be prepared for the "aren't you a little short for a stormtrooper" line... yeah, that gets old VERY fast when I hear people say that to some of our TKs.