Do you not think though that Physique competitors would be dabbling in compounds like SARMS and prohormones, which are less detectable and don't have as much stigma attached to them...
The likes of Seid surely can't be on anything too hardcore... I personally think he's been blessed with great genetics and might have dabbled with something lighter than AAS to accentuate what he's been given. His skin is unblemished, he doesn't look gnarly, vascularity isn't anything special.
I totally agree though that the likes of Piana, O'Hearn etc are on year round - and at doses that most of us would class as a blast too!
My buddy competed in the WBFF muscle model category recently, and his coach said to him 12 weeks out, that if he wanted to place, it was time to 'turn the heat up a bit' - meaning add in something other than his supps and diet... it caught him off guard, but it would have been interesting to find out what he had in mind... the coach is world renowned and has guided some top people to pro ranks.
I also fail to see how if someone like Steve Cook was dabbling in AAS, he could keep it a secret... the way the world operates these days, surely someone close to him would blab and sell a story?