A war-mage named Alexander Oluchenko Cornelius has aspirations for ruling the multiverse, invading world after world to conquer territory and expand his empire. The technology of this vast army is based on mana, which is needed to fuel its capabilities. This fuel is taken from the inhabitants of subjugated nations, who are rounded up to be "processed" by machines known as excruciators. A person is placed into one of these machines, which painfully extracts the mana from their bodies, leaving them desiccated husks. The husk can then be resurrected to serve as a mindless foot soldier in the army while their processed mana is used as fuel for the growing military industrial complex.
The problem that AOC faces is that this formula has great repercussions for the progress of his war machine, including time, cost, and effort . Excruciators slowly extract the mana from individuals over the course of thousands of years, slowing down the rate of conquest by millennia. In addition, the process is highly inefficient. Excruciators are unable to completely capture all of the mana being extracted within its chambers. This causes mana-runoff, as the mana leaks out of the machine and into the environment, causing massive amounts of pollution and ecological damage. This ultimately turns a world into a hellish landscape, unable to produce any resources of value and completely ruining the whole point of the invasion. Soldiers in the army refer to these dead worlds as "Hell", as hundreds of these worlds litter the multiverse landscape.
As a forward thinking mage concerned with the impact a conquest makes on the world's environment, it is important to be socially conscious of the ecological footprint that one leaves behind. AOC has therefore set his scientists to task building a more efficient machine that is environmentally friendly and less wasteful. This has met with success, as the next-gen model of the machine can extract mana from its subject far more quickly, providing for full extraction in decades rather than millennia. It is also built to prevent mana-leakage, allowing the machine to capture every drop of fuel from the individual. However, after this model was put into regular use, the sheer rate of return of mana from a machine is far less than before. The process of slow extraction over the course of millennia by the more primitive versions of the machine was far better at its job than its updated, higher quality model.
How can the net gain of mana be far less than before despite the improvements made to technology?