The suggestions made by Sifleg's subordinates have some merit.
But the Judge did not listen.
There are mainly two reasons:
First, this is just a conjecture. They have not implemented anything like this on a large scale before; it hasn't been proven, and the hypothesis is based only on logical inference, which may not hold true. There is still the possibility of a fight to the death between both sides, where neither gains any advantage and then is wiped out in one go by the human forces when they catch a breath.
Second, the current situation is already too urgent. If not addressed immediately, the three or four star domains surrounding Omgeria will all have to face a massive onslaught of the Green Tide directly. With the Waaagh energy accumulated by the Green Skins at their present scale, it has reached an absurd level, and it can completely guide their massive fleet, acting as a beacon, for navigation between the stars.
