I saw that a lot of readers didn't understand the realpolitik in the previous chapter, so here's a clarification.
First, in a war between the two worlds, Superbody Star had the better odds of winning. The Star Curtain World's Law Aura had nearly reached the point of irreversible decline—the process of dying with no way back. Its only chance of survival was to strike back and win before that happened. For now, the two sides were still locked in a stalemate, but every advanced civilization knew that even though the advanced civilizations of the Star Curtain World were preparing a counterattack for the final battle, Superbody Star still had a very good chance of winning the war.
Looking at things from an all-knowing perspective, I'd put Superbody Star's chances of winning at over 85%, excluding the Academic World. At the very least, the counterattack plans on each continent had some chance of working.
That's the premise behind the Black Book.
Second, A2's realpolitik didn't cost any extra resources. That's the foundation. His theory only needed to be a self-contained explanation that convinced people it was true: the universe was in the process of dying and would eventually reach heat death. That was enough to give them a moral banner, an excuse sturdy enough to support traitors, and a lofty position from which to claim the moral high ground. Even the extra energy their bodies consumed was a waste that accelerated the universe's heat death.
On that basis, once the defectors joined the Superhumans' side, they would reduce the energy lost by both sides to war, and thus reduce entropy. The Superhumans would count those saved resources as a contribution made by the defectors.
In other words, all they had to do was defect. They didn't need to do anything else;