I think guys with good genetics could still be somewhere between 200 and 220 lbs clean in shape,though not as freaky hard i think the drugs can add 10 to 20 percent to overall bodyweight over a competitors career of 10 to 15 years, i think Coleman got to around 220 to 230 cleanish, no doubt that guy and guys like Sergio Olivia are some of the most genetically gifted guys at building muscle .
I'm not a fan of GH15 theories that all guys would 190 or less just on genetics, Ive been in the sport 20 years, no doubt some of his dosages theories are up there with things some people do, but his genetic issue with no one being over 190lbs clean is unrealistic a lot of big 300lb plus permabulkers would still be 240 clean no problem, in similar shape meaning 12 to 14 percent bodyfat, Biggest advantage of using drugs, bigger and leaner. I struggled to hold muscle when dieting when i was a natural years ago, when you use, no doubt you hold the muscle and burn the fat in a much more effective way.
Just an opinion based on what Ive encountered in an around the sport before i retired.