Let's look to some Murray stats among ATGs. I consider 12 open era almost undisputable ATGs who didn't play pre-open era: Connors, Borg, McEnroe, Lendl, Wilander, Edberg, Becker, Sampras, Agassi, Federer, Nadal and Djokovic.
SLAM:
Titles: 3 (Last.)
Finals: 11 (9th tied with McEnroe, Wilander and Edberg. Better than Becker.)
Semifinals: 21 (8th. Better than McEnroe, Edberg, Becker, Borg and Wilander.)
MASTER 1000:
Titles: 14 (9th. Better than Becker, Sampras, Wilander and Edberg.)
Finals: 21 (9th. Better than Borg, Edberg, Sampras and Wilander.)
WORLD TOUR FINALS:
Titles: 1 (8th tied with Connors, Edberg and Agassi. Better than Wilander and Nadal.)
Finals: 1 (11th tied with Connors and Wilander.)
ALL TOURNAMENTS:
Titles: 46 (11th. Better than Edberg and Wilander.)
Finals: 68 (12th. Better than Wilander.)
ATP RANKING:
YE #1: 1 (10th tied with Wilander and Agassi. Better than Becker.)
Weeks #1: 41 (11th. Better than Wilander and Becker.)
Weeks Top 3: 226 (12th. Better than Wilander.)
Weeks Top 5: 429 (11th. Better than Borg and Wilander.)
Weeks Top 10: 494 (11th. Better than Borg and Wilander.)
ELO RATING:
Peak: 2500 (7th. Better than Connors, Becker, Sampras, Wilander, Agassi and Edberg.)
Best Season End: 2500 (7th. Better than Connors, Becker, Agassi, Sampras, Wilander and Edberg.)
PERFORMANCES:
Total Wins: 673 (11th. Better than Borg and Wilander.)
Win Rate: 77,45% (8th. Better than Sampras, Becker, Agassi, Edberg and Wilander.)
Slam Wins: 189 (8th. Better than Edberg, McEnroe, Becker, Wilander and Borg.)
Slam Win Rate: 80,77% (10th. Better than Becker, Wilander and Edberg.)
CONCLUSION:
Although he is ranked in the lower half almost everywhere, he isn't ranked last alone(So worse than all ATGs) in any stat, aside Slam Titles.
He is better than or tied with Wilander in every stat, aside Slam Titles.
For comparison, a player often considered to belong to Murray's Tier like Jim Courier, making the same comparison with same 12 ATGs would be ranked last alone in 16 out of 20 stats(All but both WTF stats, YE#1 and Weeks #1).
This analysis not even considered two Olympics Titles because their value is debatable.
I agree the worst stat for Murray is the most important one. But for me it's really hard not consider him an ATG since he scores so well in every other metric.
SLAM:
Titles: 3 (Last.)
Finals: 11 (9th tied with McEnroe, Wilander and Edberg. Better than Becker.)
Semifinals: 21 (8th. Better than McEnroe, Edberg, Becker, Borg and Wilander.)
MASTER 1000:
Titles: 14 (9th. Better than Becker, Sampras, Wilander and Edberg.)
Finals: 21 (9th. Better than Borg, Edberg, Sampras and Wilander.)
WORLD TOUR FINALS:
Titles: 1 (8th tied with Connors, Edberg and Agassi. Better than Wilander and Nadal.)
Finals: 1 (11th tied with Connors and Wilander.)
ALL TOURNAMENTS:
Titles: 46 (11th. Better than Edberg and Wilander.)
Finals: 68 (12th. Better than Wilander.)
ATP RANKING:
YE #1: 1 (10th tied with Wilander and Agassi. Better than Becker.)
Weeks #1: 41 (11th. Better than Wilander and Becker.)
Weeks Top 3: 226 (12th. Better than Wilander.)
Weeks Top 5: 429 (11th. Better than Borg and Wilander.)
Weeks Top 10: 494 (11th. Better than Borg and Wilander.)
ELO RATING:
Peak: 2500 (7th. Better than Connors, Becker, Sampras, Wilander, Agassi and Edberg.)
Best Season End: 2500 (7th. Better than Connors, Becker, Agassi, Sampras, Wilander and Edberg.)
PERFORMANCES:
Total Wins: 673 (11th. Better than Borg and Wilander.)
Win Rate: 77,45% (8th. Better than Sampras, Becker, Agassi, Edberg and Wilander.)
Slam Wins: 189 (8th. Better than Edberg, McEnroe, Becker, Wilander and Borg.)
Slam Win Rate: 80,77% (10th. Better than Becker, Wilander and Edberg.)
CONCLUSION:
Although he is ranked in the lower half almost everywhere, he isn't ranked last alone(So worse than all ATGs) in any stat, aside Slam Titles.
He is better than or tied with Wilander in every stat, aside Slam Titles.
For comparison, a player often considered to belong to Murray's Tier like Jim Courier, making the same comparison with same 12 ATGs would be ranked last alone in 16 out of 20 stats(All but both WTF stats, YE#1 and Weeks #1).
This analysis not even considered two Olympics Titles because their value is debatable.
I agree the worst stat for Murray is the most important one. But for me it's really hard not consider him an ATG since he scores so well in every other metric.