The best genetics I've seen were from this Nigerian guy at my gym. He was an accountant but seemed like a sincere guy. Trained arms every day and never lifted heavy. A protein shake post workout was the only supplement he took. The rest of his diet was tinned tuna and his traditional foods.
This guy looked insane! Paper thin skin, vascular and full, low body fat, tiny waist and thick chest/arms. Never trained legs because he played five a side football (soccer) but started after I told him the benefits of squats. He looked like he could walk on stage any minute.
This guy I'm sure was natural. I doubt that even on grams of gear I would have matched the sheer quality of his build.
Some of these West African guys are just crazy. So many with the potential to suppress even Ronnie and Wheeler if they ever decided to get serious.