Don't quite get your point! Yes, I am aware of who Kim McDonald was, and while he coached some of the athletes mentioned, he was only a 'manager' of others. I do not recall ever reading that Mcdonald had any influence on the career or training of Ovett. Eliott I am aware of.
What you need to consider is when he was coaching/managing these athletes, where they were in their career projectories, and also you need to figure in the fact that certain African countries had no out of season testing (until very recently) by their own federations. An athlete from most European nations (and others around the World) would have had to submit their whereabouts for testing every day of their careers. This would not have been the case for Ngeny, for instance. It would therefore be much easier for an athlete from a nation that has no testing, to dope at strategic times of the year, probably when training at altitude in some remote part of Africa where even the IAAF testers would seldom if ever visit due to logistical proximity to nearest testing lab in Europe.
In addition, just because 1 athlete in one era is doping, it doesn't necessarily mean that another athlete with the same coach in a different era was also doping with EPO. If the athlete wasn't competing at elite level between c. '93 and '06, then it is less likely they were using EPO. Unfortunately, due to sheer lack of testing, many African athletes and those from countries around the world deemed too poor to afford OOS random testing for their athletes, are more likely to have used EPO during this era (especially before 2000, when the first test for EPO became available).
I think McDonald started to train Kenyans in the mid 80's, but the real effects of his training weren't realised until the mid 90's, when he coached Ngeny, Kiptanui and Komen. It could be just a coincidence that all those WRs were set by Kenyans in the late 90's (not to mention the likes of EL G and Geb knocking huge chunks of the WRs), at a time when there was no test for EPO. Or it could be a bit more than that. And even if any of those did take EPO, it doesn't automatically follow that their coach/agent was aware of it.
However, it is unfortunate (but should be remembered) that Mcdonald did have a close working relationship with Dieter Hogen. He who went on to head the Kimbia stable and was a product of the GDR system in the '80's, having been trained by Berndt Diessner alongside Straub and Beyer; the latter of course was named in documents uncovered after the German unification as one of a number of athletes on a state sponsored drug scheme; and one wonders how Straub ran so far above himself in one solitary race in Moscow! Hogen is also married to ex German marathon runner, Uta Pippig, herself banned for PED use in 1998 (caught by a random out of season test).
Hindsight is a wonderful thing, but I came across this thread (see link below) from here 15 years ago, in which one of the discussion points (PEDs) was attempted to be dismissed by someone stating that they knew/believed that Aficans were clean-
'Ask people that actually know the sport (as opposed to those who subscribe to the "they ran fast so they're on drugs" dogma) and you will find that the most suspicious athlete believes the KIM group, and the majority of Kenyans in general, to be clean. For instance, Jon Brown who has been perhaps the most outspoken against cheating and has not been bashful in naming names was recently quoted to the effect of, "by and large the Africans are clean."'
Now, while of course it is a nonsense to state all Africans are doping, unfortunately their recent record of drug busts (in the same way as Russia, but without the sanctioned state sponsoring) is not great and I certainly do not buy into the argument quoted above, especially not for the period 93 - 06.