It looks like Nettles was a very good defensively. According to Baseball Reference's defensive metrics he was 3.6 wins above replacement defensively in 1976, 2.7 in 1973, and then had a bunch of years ranging from 0.5 - 1.9. Very good defensively and better than Arod, who, as a Yankee, has been average to slightly above average defensively.
The problem for Nettles is that his bat is so far below Arod's that his glove can't make up the difference. Arod has had two 9+ WAR seasons with the bat alone as a Yankee. Another over 8, and a few in the 5's and 6's. Nettles really can't come anywhere close to that.