[eru]

Well, but they aren't doing so right now, because labour has costs.

If your existing labour suddenly gets more productive, there's still a trade-off between cost and benefit to be made. And it would be a great coincidence if the optimal trade-off were exactly at the same headcount as the old trade-off under the old productivity figures.

It's more likely that the optimal trade-off for the business under the new conditions is at some other headcount.