I feel like if a eugenics program dwindles your population so hard that you literally have a ring around your planet of corpses and there's only 50 of you left it crosses from gritty and fucked up to comical and retarded.
There is no way the "rah rah strength is everything purge the weak" logic would run that deep and becomes that self-destructive for a full blown space-fairing civilization with a deep understanding of biology and logistics. They would have to be outright moronic to not think that far ahead.
Like what's the ultimate goal of the Viltrumite philosphy, that there would just be one singular ultimately-powerful Viltrumite left alone in the universe by the end? Clearly not given they have intergalactic breeding programs because their population is too low and the Empire is fraying apart, so what the fuck was the point?
Saiyans in DBZ at least make sense. They venerate fighting and strength because it thrills them on a biological level. It's literally ingrained in their DNA to love the thrill of combat for the sake of it so that became a normal part of Saiyan life.
But they aren't eugenicists, Saiyans with low power levels are bullied and called weak but they aren't culled or purged. Fighting is just a part of the culture, not an active ideological position like with Viltrumites.
For Saiyans becoming stronger is the journey, but for Viltrumites it's the goal. A retarded one, as is obvious.