Let me start by saying, honestly, kinda cringed at the comparison to Breedtown given it is at the heart of why I do NOT do that. I didn't want to make Norah, Zorah, Saki, Mery, and the other girls unmemorable bags of flesh you fill full of seed and forget... This is why I am dropping a 34,000-word update that expands a lot on many characters, adds even more, and so on... This is an alpha. A half-completed alpha. Things aren't going to be perfect, BUT I am working... as one guy... To improve this as a whole.
I can point out a game that makes mass pregnancy make sense but also provides a story for the reasoning: Hazumi and the Pregnation. However, I do not wish to make Hazumi 2, I want to make a game where the pregnancies have value to all involved.
I am a first-time dev. Some things that have been done might not meet my intended goal, but my goal is legit. Even if appearances might not be as adequate to some as I intend to appear. This is why I might take a break after the completed alpha and survey things and my goals and see how to improve upon things to realize this concept's full potential...