Sounds silly, does it not? Djokovic leads both H2H. Actually right now the domination of his main rivals is probably the main argument why Djokovic should be the greatest, probably because he (right now, may change) does not have anything else (sheer numbers like Federer or surface domination like Nadal). So he probably have the best H2H in history, right?
Lets take a look and put his numbers in historical context, shall we?
For reference I use 10 GOATs as per UTS (Federer, Djokovic, Nadal, Sampras, Agassi, Becker, Lendl, Connors, McEnroe, Borg).
Between those 10 players were 22 rivalries where one player won more matches than the other. 19 cases out of 22 (86,4 %) it was the younger ATG who won the rivalry. Younger ATGs won 59 % of all matches, while the older one just 41 %. Djokovic has just older ATGs, however is not nearly as good as the other ATGs were in putting them down. His winning percentage is 52,5 %, 6,5 % percentage points worse than "average" ATG. Not too good for supposed "H2H king".
Unluckilly for Djokovic this is not all. There is one more historical truth - younger ATGs are even more dominant in the most important matches - in grand slam tournaments. While they won 59 % of all matches, they also won 65,5 % (and 71,1 % if counting all ATGs but Djokovic) of GS matches and again 19 out of 22 (86,4 %) rivalries. The lost rivalries from perspective of younger ATG are: Becker/McEnroe (1 match), Agassi/Lendl (2 matches where Agassi was 18, respective 19. Did not play GS match ever since) and Djokovic/Nadal (15 matches)...
Djokovic played 29 matches against older ATGs and won just 14 of them (48,3 %). That is 17,2 percentage points worse than is ATGs average and even 21,8 % percentage points worse if we discount Djokovic from average (therefore he is almost 50 % worse than others are). He is also the only ATG who has negative collective H2H against older ATGs.
For reference here is winning percentage in GS (first) and overall for each player against older ATGs:
Connors 0 (no older OE ATG)
Borg 61 %, 65,2 %
McEnroe 69,2 %, 56,3 %
Lendl 61,1 %, 57 %
Becker 75 %, 66 %
Agassi 70 %, 57,1 %
Sampras 80 %, 63,6 %
Federer 80 %, 75 %
Nadal 76,9 %, 62,5 %
Djokovic 48,3 %, 52,5 %