2011-2013 Djoker had the benefit of having his peak body,but objectively 2014-2016 Djoker is the better player.
2011 Djoker was a beast,better than any other version,but that had little to do with any influence from a coach,it was simply Novak showcasing his potential.
However,their were certain improvements in 2014 as opposed to 2012 and 2013,it is just that unfortunate events made Djokovic underperform that year.
Lack of training during NA swing,low-confidance at AO,sick in the RG final. When fit and motivated,he won IW-Miami double,played very well on grass+indoors and another exceptional display in the Rome final.