Channel 9 of the Merge will map to channel 5 because the poly cable is setup to process stereo signals as follows:
chan1 of poly cable is Track 1 - left
chan2 of poly cable is Track 1 - right
chan3 of poly cable is Track 2 - left
etc.
Also, the normal way to connect EQ master is thougth the insert chain only. This means the insert out goes to the EQ in, and then the EQ out goes back to the insert in. Hope this helps!
This is how it is normally cabled on the inserts. This gives you EQ on the first 8 tracks of MixMaster. Select the track you want to EQ using the Track knob on EQMaster.