No, it isn't since the ATP Finals/Masters Cup is not as relevant as Grand Slams. The number of Grand Slams is the most relevant all-time great criterion. Other criteria such as Masters Cup or Masters 1000 are just tie-breakers in case two players are tied in Grand Slams. Nadal would choose another AO over his first MC any day. Federer and Djokovic would also choose another AO over their first Olympic Gold in singles.yes the aussie open is big and only three months away but for nadal the tennis masters cup is even bigger...
Wilander has 7 Grand Slams and no Masters Cup, while Murray has 3 Grand Slams and the ATP finals/Masters Cup. Yet, most people rank Wilander over Murray:
It proves that people rank higher the Grand Slam count than having the Masters Cup.