I didn't say that no Kenyan could run sub 3:33 clean, I said that any Kenyan performance faster than that (well any elite Kenyan performance really) should now be seen as suspect. I think I might have raised the question as to whether Kenyans could even run faster than 3:32 clean in the emotive thread I started immediately after the Kiprop bust.
I know it's hard for most of you to understand here, but a small minority of people on this forum do actually love the sport, and really are hurt and angered when the Kenyan GOAT at 1500 is exposed as a drug cheat (and more than that, the comical testing standards in Kenya exposed).
I'm not going through all my arguments again, but it does seem odd to me that Kenya cannot produce a real world class performer in any other sport, despite running (and aerobic fitness in general) being the basis of so many different sports. That they dominate it to the extent they do, and almost overnight as well.
Before 1989, no Kenyan had broken 3:33. Between 1990 and 1995, only 3 Kenyans did, all running 3:32. So as recently as 1995, the Kenyan record was still nearly 3 seconds slower than the European record, and 1 second slower than the New Zealand record.
Then the floodgates opened.
Between 1995 and 2000 15 Kenyans ran under 3:33, twelve of them ran under 3:32, and four ran under 3:30. The Kenyan record had improved by 5 seconds in just 5 years, and was now 2 seconds faster than the European record.
I wonder what was happening in the pharmaceutical world in the early 90s? Oh yeah, I remember.
It seems quite possible to me, given especially what we now know about the doping situation in Kenya, that every single Kenyan performance under 3:32 (or whatever) was doped. That's not to say that no Kenyan could run under 3:32 clean, but that it's more than possible that all the elite Kenyans are/were doped and so we don't know.
As to your question, I think Coe, Cram, Ovett were all clean, or at least I think it highly unlikely all three were doping. As all 3 could have ran 3:28 in the right circumstances even back then, let alone today, I think the clean limit is probably around 3:27. I don't think there is a limit tbh, or at least it moves back very slowly as little improvements in collective training knowledge, shoes, tracks, nutrition continue.
It's quite possible that Jakob could eventually run a really crazy time, and do it clean. All the ingredients are there, such as being a unique talent possibly only seen in the half a dozen or so individuals in the last 50 years (such as Coe, Ryun, Ovett, Cram, Herb Elliott, Snell), and with the benefit of having the brothers to mentor him etc. Of course, luck plays a part in any ahtlete's progression, but he appears to have all the talent and the right environment.