Maddux was a great fielder....but there is almost zero chance he deserved all 18 of those Gold Gloves. The award is almost entirely reputation based and has pretty slim correlation to actual ability. Once he had won 4-5 in a row, he was essentially guaranteed the award until he stopped playing
See: Derek Jeter's FIVE awards..
...and of course, my favorite Gold Glove anecdote ever, Rafael Palmeiro won the 1999 Gold Glove despite playing only 246 innings in the field (across 28 games). He made 128 starts at DESIGNATED HITTER.
So yeah, Maddux >>>> , but GGs are stupid.