lmao
What little bit of DNA they actually took from Shaun probably has very little in common with the Gen-3s. At most, it would be like banging a random stranger (although, any Synth would probably be that same stranger... so Synth on Synth action, on the other hand ).
incist people? Really? Highly doubtful.
These are machines with some human DNA thrown in, not actual living breathing human beings. Not incist. You're fraking a toaster.
On the surface it may appear that way.
Synths are closer to Jurassic Park Dinosaurs, then Cloning.
They used shauns *uncorrupted* DNA to fill in the missing gaps of the human genome sequence so that they may synthetically build humans with their machines. This allows the DNA sequences to be varied, and unrelated. Otherwise all Synths would be genetically related, and easy to sort out from other human beings. We know this because of "Blind Betrayal" Where the Institutes DNA records matched the DNA records kept on another person in the commonwealth.
So Father is more of a term in the sense of creation, and is philosophical. Not entirely "Half of your DNA is mine." Biological