If Futa's can breed others, they need to have balls. Futa-Trans is not about balls at all. You talk about logic and you throw it from window at your next statement. The only reason is dev does not want see balls. The game got males because of the money as the dev hates any male visuals. I don't blame someone for his choices but the reason is not "this is a breeding game", it's just because Dev does not want it.
As others already said, there is an oral sex. You try to defend it as pre-sex but as they cum at oral sex, it's no point at a breeding game too. If the dev wanted it, there could be many reason for any kind of interaction like by giving buffs or leveling up the characters. Those can be disabled at options and everybody would be happy and probably most record breaking adult game out there but nope.
Fun part is dev is not playing his own game at least for 5+ years so..