I disagree. It was a key point in the FO1 plot that there is a significant difference between regular [exposed] wastelanders and the prime normals that remained sealed in the vault for most of their life. Prime Normals tended to survive the dip with their mind intact [more often than non-primes]; It's (possibly) the difference between Harry & Larry and the Leiutennant.
I think the Enclave were full blown genocidal ~where damaged [or altered] genes were concerned; and generally evil aside from that. Remember, the Enclave exchange operator casually sent a kill team to Gecko [to murder whomever they found present] then gloated about it ~to a total stranger that merely logged into their network from a live terminal. Sent a killer team to murder whomever they found, and he'd read about it in the after action report.
And that mutation that you are talking about is radiation.
A good quality super mutant is low levels of radiation + FEV.
I am not disputing that. What I am saying is there would be plenty of people who were not exposed to radiation and thus, a prime normal.
BoS, Vault Dwellers, and any other person who had a quality shelter and took precautions. For example the Survivalist in Honest Hearts. People in rural areas. The Master was making just fine SM, and he wasn't raiding Vaults for all those people, meaning that many of his SM were regular wastelanders, who had not been exposed to much radiation. Vault 13 folk would be great.
The FO world did not have a nuclear winter. Yes, there were people who got screwed. But there would be a good chunk who did not. By the time of FO2, even FO1, radiation isn't running rampant. A lot of people in the games all had shelter. Vault 15 raiders and shady sands. Vault City.
That is point of my entire argument. If mutation caused by radiation, then there would be plenty of people who were protected. But then people try to say oh well it not just radiation it also FEV and umm it still floating around for 160 years. And I say no cause that would totally contradict lore and it would have created ALL kinds of problems in humans that we NEVER see in game.
The Enclave just uses this as an agenda and method of control over their people. If they were that concerned with pure or non pure, the Curling virus would have only affected non pure. It would protect them and kill all non pure. They are not concerned because they only care about themselves.