Avocados Number, you're chasing your tail armed with classic Letsrun Circular Logic.
My statement that Virgin was the fastest runner in the field in 1981 is backed with irrefutable empirical evidence. He was faster - end of story. Additionally Virgin had beaten both Mamede and Kedir heads up. END OF STORY. Wishing for a fantasy result that didn't and won't ever happen, by arguing with classic Letsrun Circular Logic - presenting your premise as proof that your premise is true - is silly.
Virgin was the dominant runner in 1980 and 1981. You can't change that.
Virgin had clearly demonstrated his mastery over both Kedir and Mamede.
1980 World cross
1 37:01 Craig Virgin (1955.08.02) 24.220 USA
2 37:02 Hans-Jürgen Orthmann (1954.02.05) 26.033 FRG
3 37:05 Nick Rose (1951.12.30) 28.070 ENG
4 37:11 Léon Schots (1952.06.11) 27.272 BEL
5 37:20 John Robson (1957.01.31) 23.038 SCO
6 37:21 Aleksandr Antipov (1955.03.09) 25.000 URS
7 37:21 Leonid Moseyev (1952.10.21) 27.140 URS
8 37:21 Antonio Prieto (1958.01.11) 22.058 ESP
9 37:23 Steve Jones (1955.08.04) 24.218 WAL
10 37:25 Bernie Ford (1952.08.03) 27.219 ENG
11 37:27 Karel Lismont (1949.03.08) 31.001 BEL
12 37:28 Daniel Dillon (1957.06.25) 22.258 USA
13 37:31 El Hachami Abdenouz (1956.07.01) 23.252 ALG
14 37:33 Barry Smith (1953.04.16) 26.328 ENG
15 37:39 Thierry Watrice (1957.01.23) 23.046 FRA
16 37:42 Fernando Mamede (1951.11.01) 28.129 POR
17 37:44 Steve Kenyon (1951.09.16) 28.175 ENG
18 37:44 John Treacy (1957.06.04) 22.279 IRL
19 37:47 Nick Lees (1958.01.23) 22.046 ENG
20 37:48 Klaas Lok (1955.01.12) 25.057 NED
21 37:49 Alex Hagelsteens (1956.07.15) 23.238 BEL
22 37:51 José Luis Gonzalez (1957.12.08) 22.092 ESP
23 37:53 Kenneth Martin (1958.09.10) 21.181 USA
24 37:54 Dominique Coux (1950.01.06) 30.063 FRA
25 37:54 Alex Gonzalez (1951.03.16) 28.359 FRA
1980 World 10k list
1 Craig Virgin USA 27.29.16 1 Paris Jul 17
2 Henry Rono KEN 27.31.68 1 Melbourne Feb 6
3 Fernando Mamede POR 27.37.88 2 Paris Jul 17
4 Miruts Yifter ETH 27.42.69 1 Moscow Jul 27
5 Toshihiko Seko JPN 27.43.44 1 Stockholm Jul 7
6 Kaarlo Maaninka FIN 27.44.28 2 Moscow Jul 27
7 Aleksandr Antipov URS 27.44.58 2 Stockholm Jul 7
8 Mohamed Kedir ETH 27.44.64 3 Moscow Jul 27
9 Tolossa Kotu ETH 27.46.47 4 Moscow Jul 27
10 Bill Scott AUS 27.46.71 2 Melbourne Feb 6
11 Kunimitsu Itoh JPN 27.47.35 3 Stockholm Jul 07
12 Gerard Tebroke NED 27.48.33 4 Stockholm Jul 07
13 Hideki Kita JPN 27.48.59 5 Stockholm Jul 07
14 John Treacy IRL 27.48.7 1 Brussels Aug 22
15 Alberto Salazar USA 27.49.3 2 Brussels Aug 22
16 Lasse Viren FIN 27.50.46 5 Moscow Jul 27
17 Alex Hagelsteens BEL 27.50.6 3 Brussels Aug 22
18 Werner Schildhauer GDR 27.53.51 1 Potsdam May 31
19 Stephen Austin AUS 27.54.3 1 Melbourne Dec 18
20 Enn Sellik URS 27.55.41 6 Stockholm Jul 07
21 Tekle Fitinsa ETH 27.57.7 4 Moscow Jun 12
22 Bill McChesney USA 27.58.5 3 Paris Jul 17
23 Martti Vainio FIN 28.00.64 1 Helsinki Jul 09
24 Matthews Batswadi RSA 28.00.72 1 Port Elizabeth Apr 11
25 Hansjörg Kunze GDR 28.00.73 2 Potsdam May 31
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1981 World Cross
1 35:05 Craig Virgin (1955.08.02) 25.238 USA
2 35:07 Mohammed Kedir (1953.09.06) 27.203 ETH
3 35:09 Fernando Mamede (1951.11.01) 29.147 POR
4 35:13 Julian Goater (1953.01.12) 28.075 ENG
5 35:18 Antonio Prieto (1958.01.11) 23.076 ESP
6 35:20 Rob de Castella (1957.02.27) 24.029 AUS
7 35:22 Girma Berhanu (1960.07.19) 20.252 ETH
8 35:23 Thom Hunt (1958.03.17) 23.011 USA
9 35:24 Alex Hagelsteens (1956.07.15) 24.256 BEL
10 35:26 Pierre Levisse (1952.02.21) 29.035 FRA
11 35:30 Rod Dixon (1950.07.13) 30.258 NZL
12 35:34 El Hachami Abdenouz (1956.07.01) 24.270 ALG
13 35:39 Dereje Nedi (1954.01.13) 27.074 ETH
14 35:40 Kebede Balcha (1951.09.07) 29.202 ETH
15 35:42 Miruts Yifter (1944.05.15) 36.317 ETH
16 35:42 Martti Vainio (1950.12.30) 30.088 FIN
17 35:42 Mark Nenow (1957.11.16) 23.132 USA
18 35:42 Bill Donakowski (1956.06.21) 24.280 USA
19 35:42 Bruce Bickford (1957.03.12) 24.016 USA
20 35:46 Roger de Vogel (1955.09.22) 25.187 BEL
1981 World 10k list (Virgin ran Boston Marathon, then hit the road scene)
1 Fernando Mamede POR 27.27.7 1 Lisboa May 10
2 Werner Schildhauer GDR 27.38.43 1 Rome Sep 4
3 Mohamed Kedir ETH 27.39.44 2 Rome Sep 4
4 Alberto Salazar USA 27.40.69 3 Rome Sep 4
5 Henry Rono KEN 27.40.78 1 Brussels Aug 28
6 Venanzio Ortis ITA 27.42.70 4 Rome Sep 4
7 Geoff Smith GBR 27.43.76 1 Dresden Jun 13
8 Martti Vainio FIN 27.45.50 1 Oslo Jul 11
9 Bill McChesney USA 27.47.25 2 Oslo Jul 11
10 Julian Goater GBR 27.47.54 2 Brussels Aug 28
11 Carlos Lopes POR 27.47.8 2 Lisboa May 30
12 Suleiman Nyambui TAN 27.51.73 1 Stockholm Jul 08
13 Toshihiko Seko JPN 27.51.93 2 Stockholm Jul 08
14 Stephen Austin AUS 27.53.30 3 Stockholm Jul 08
15 Toomas Turb URS 27.54.18 6 Rome Sep 04
16 Markus Ryffel SUI 27.54.99 3 Brussels Aug 28
17 Alex Hagelsteens BEL 27.55.06 4 Stockholm Jul 08
18 Mike McLeod GBR 27.59.42 1 Prague Jun 19
19 Nick Rose GBR 27.59.68 3 Prague Jun 19
20 Steve Jones GBR 28.00.58 6 Prague Jun 19
21 Rafael Marques POR 28.02.20 3 Lisboa May 30
22 Antonio Prieto ESP 28.02.71 10 Prague Jun 19
23 José Sena POR 28.02.80 4 Lisboa May 30
24 Miruts Yifter ETH 28.03.23 2 Pisa Aug 26
25 Tolossa Kotu ETH 28.03.25 11 Prague Jun 19