Originally Posted by
indyfabz
They all looks counterfeit.
See, e.g.:
RD-TZ50-GS (shimano.com)
Notice difference in, among other things, the cages between the one from the official Shimano site and the crap posted near the top.
Counterfeit parts would explain a lot. I wonder if there's a "high-end" bike shop near O.P. that sells real Shimano parts, or has Gresham's law taken care of that possibility?