Other teams haven't needed to be, or haven't taken that investment to the extreme. I think there are probably three or four national squads who can run a similar train:
GB -Cav
US - Farrar
Aus - Goss
Germany - Greipel
I don't think any other national team could do as well.
We know that Garmin and Sky can both put together credible leadout trains when required, though Highroad are the absolute masters (the confidence of knowing that if you don't stuff up, Cav will win - and the corrollary for the opposition, knowing that even if you don't stuff up, Cav will win)
Omega Pharma Lotto/Lampre/Liquigas also stepped up to the mark occasionally but never quite got to the same level.
Looking at the Worlds, I'd put the GB train as probably the best with US second and probably AUS third.