I initially slotted it in the far right (because torps usually-but not always-tend to fire left to right) but then I played around with it. Seems to make no difference... always takes firing priority over other torps.
I do the same thing, especially when employing shield subsystem attacks. Typical Escort forward weapon set-up is (from left to right) beam array - DHC - DHC - Torpedo Launcher. This allows energy weapons to hit or weaken shields first, just before the torpedo hits its target.
Unfortunately I won't have access to the Omega Torpedo for at least 2 more days, but I'm patiently watching the in-game clock