I agree in everything you are writing here, and I also think Ovett would have been competitive in every time period. But here is the thing: I don’t think Ovett chose to be competitive to be one among the all time greats! And why does that matter? Simply because he could have been…
To me the all time greats are (from 800m and above, and in modern times): Rudisha, Kipketer, H.Elliott, Haile, Bekele, Komen, Morceli, El Guerrouj, Ngeny, Lagat, Kiprop- (a minus for a “may be” positive sample in a shady doping case), Ingebrigtsen, Kipchoge, Kiptum, Kiplimo, Cheptegei. (I have let out some who still is in progress, like Girma and Kejelcha, and likely forgotten one or two or more..).
Borderline all time greats: Coe, Cram, Cheruiyot, Kipsang, Mo Farah (because of his 1500m times in addition to being a distance runner),Aouita.
Great, but not even borderline all time: Ovett, among others.
Well, I think Ovett had it in him to be an all time great (his 2 mile WR sort of showed some potential, although to soft because he let Henry Rono do all the work, and he (being born in another time) could have learned from Jakob to show boat in a sympathetic way, and from Kipyegon to feel some shame over being towed… Cram, Cheruiyot and Mo clearly also could have been up there, but not Coe I think. -He seems to have fulfilled his potential -I don’t know if he trained in a restricted way, or lacked the others’ talent (maybe fast twitch over slow twitch always is bad for a miler and above) -his two Olympic golds means nothing to me; all times greats run fast, and his 1.41,7 and 2.12 or 3.29.7 aren’t fast enough…
Guess I will earn some downvotes -but honesty before politically correctness… And apologies to the all time greats I may have forgotten.