Due to the large tolerances in the impedance of pull-down resistor on the RST line I wouldn't simply put the reset lines in parallel if I would want to be sure a proper reset is generated. Yes, if you are making a reset by pressing a simple button things will probably work most of the time, but I believe that it is also necessary to get a proper reset in case of a short power interruption.

As using a simple RC reset is a bad idea in the first place, I would recommend using a reset circuit if anyone asks me.