Before that idea goes too far in either direction, you should note that the Twelve weren't summoned. Their strength was conjured and tapped into, but Louisoix stopped short of summoning any more than that. That's why the ritual failed - he underestimated what was needed. If the Twelve were fully summoned, they'd have succeeded in binding him - but possibly at the cost of bleeding the planet dry, which is the outcome they were trying to prevent by sealing him in the first place.