You're ignoring a whole hell of a lot of context for Komen and Guerrouj doping. Komen ran for survival, he had very little incentive to not dope. His 7:20 was run with some of the worst pacing I've ever seen, and he could only muster a 59.6 last lap. He did it on the old and (admittedly fast but not modern Mondo) and terrible spikes. In the height of the EPO era with no test.
Guerrouj has already been discussed ad nauseam - the height of his powers coincide exactly with the EPO era and he retires as soon as a test for EPO is announced only aged 30. 5 times 3:26.X 1500's in the old spikes and tracks, training group heavily associated with doping.
I agree with your sentiment about Ruth and Shelby. Shelby 100% doped. To me Ruth seems highly likely but without a positive is not a slam dunk, much like Komen and Guerrouj.
All that being said, I will never vouch for anyone being clean or not clean that I don't know. I can't say I'd be terribly surprised if it came out eventually that Ingebrigtsen doped... however, I think even if he ever did test positive he's more in the too big to fail category.