Well, generally speaking, you should be able to do this. I just hooked up a TimeFactor to an H9 running the latest firmware, and the H9 was following the TimeFactor's tempo correctly:
https://dl.dropboxusercontent.com/u/1383432/MidiClock.MOV
Could you try hooking up just your two H9s directly — configuring the first H9 to transmit MIDI Clock and the second H9 to receive MIDI Clock — to see if you can get the second H9 to follow the tempo of the first one?
