Track and Field news has a list of the all-time DL winners.
Here are the men''s 3000/5000 winners.
5000 METERS (some meets run 3000s)
2010 Imane Merga (Ethiopia)
2011 Imane Merga (Ethiopia)
2012 Isiah Koech (Kenya)
2013 Yenew Alamirew (Ethiopia)
2014 Caleb Ndiku (Kenya)
2015 Yomif Kejelcha (Ethiopia)
I don't see Mo Farah on that list. In their primes, Haile G and Kenny B were so much better than everyone else they would have won that and Olympic gold.
It's also worth pointing out that Ezekiel Kemboi hasn't won one either.
STEEPLE
2010 Paul Koech (Kenya)
2011 Paul Koech (Kenya)
2012 Paul Koech (Kenya)
2013 Conseslus Kipruto (Kenya)
2014 Jairus Birech (Kenya)
2015 Jairus Birech (Kenya)
Full list here:
http://www.trackandfieldnews.com/index.php/archivemenu/35-stats/2433