Bill,
You're right, the card doesn't care how but there sure are various ways of getting to how many and I think these 3 examples show that.
-In 2005, Garcia was #1 in GIR but 196th in putting average, 197th in putts per round, and 30th in par breakers (the percent of the time a player is under par for a hole).
In 2005, DiMarco was 125th in GIR but 10th in putting average, 20th in PPR, and 97th in PBs.
-In 2005 Woods was 6th in GIR, 5th in PA, 33rd in PPR and 1st in PBs.
Garcia(#10 on the money list) appears to be living by his ball striking, not his putting, although he does take advantage of holes that he likes.
On the other hand, DiMarco(#7 on the ML) tends to rely more on putting than ball striking.
Woods(#1 on the ML) has both putting and ball striking going for him.