First off, MacMillan is useless for anything but road times. IAAF gives 14:08 = 8:52. Impressive as hell for seven guys, even if one is a 20-something Kenyan running 13:41.
None of those Japanese girls is a threat to Cain in any way, she was 3 seconds faster as a junior in HS, with a withering kick, and Alexa would beat them as well.
Let's look at the W Jr champs from last summer:
M5000 Final:
9 1535 Colby GILBERT USAUSA 14:09.98
10 153 Morgan MCDONALD AUSAUS 14:10.08
11 932 Kazuto KAWABATA JPNJPN 14:10.14
I've never even heard of Colby Gilbert, and he beat the top Japanese representative. Are the Japanese running all these kids in an Ekiden instead?
W3000 Final:
1 Mary CAIN USAUSA 8:58.48 PB
2 992 Lilian Kasait RENGERUK KENKEN 9:00.53
3 988 Valentina Chepkwemoi MATEIKO KENKEN 9:00.79 PB
4 960 Nozomi Musembi TAKAMATSU JPNJPN 9:02.85 PB
5 582 Etagegn WOLDU ETHETH 9:06.42
.......
11 963 Nao YAMAMOTO JPNJPN 9:24.41
12 1250 Maria Magdalena IFTENI ROUROU 9:26.04 PB
13 1515 Nataliia SOLTAN UKRUKR 9:26.58 PB
14 994 Darya MASLOVA KGZKGZ 9:30.28
15 1600 Stephanie JENKS USAUSA 9:31.47
A little better for the Japanese girls, but still not overwhelming.