This is the way I connect both H9

but the thing is that the 1st H9 it has to be ALWAYS in pre, because if I put it in POST, the audio signal comes from the FX Loop and it blends the clean signal from the guitar and the fx signal 

so is the same thing to plug it like this or to put one in front and one in the fx loop, since I cant change the input of the signal flow 

unless I am doing something wrong…