Headscratchers / My Uncle Oswald

• OK, let's consider the following: 1) It is not only hinted at but eventually explicitly confirmed that Oswald is not above unethical fraud, even if the marks are his own partners. 2) Oswald is able to very successfully forge even royal signatures without arousing any suspicion. 3) Oswald does not really aim at "breeding geniuses", as he puts it, and he's not even sure that all those phenomenal qualities can be inherited in the first place. So an obvious question is this: Is there any Watsonian reason why he shouldn't just forge all those geniuses' and kings' signatures on the certificates and sell just any sperm of the roughly look-a-like person (with somewhat similar color of hair, eyes, skin and maybe height so that the switch isn't immediately obvious after the baby is born)? Yes, eventually the fraud would probably be exposed but by that time he'll have been long gone with the loot. The whole thing would have become MASSIVELY easier for him to pull off.