I think at their respective peaks, Murph was a comparable all-around player. Certainly his career numbers don't match up, I know.
1937: .346 BA, .673 SLG%, 46 HRs, 167 RBIs, 37 strikeouts.
1939: .381 BA, .671 SLG%, 30 HRs, 126 RBIs, 20 strikeouts
1940: .352 BA, .626 SLG%, 31 HRs, 133 RBIs, 30 strikeouts
Give me Murphy's three best years and we'll stack 'em up.
(And also remember that teams played 8 fewer games per season in Joe D's era).
As far as outfield prowess is concerned, Murphy was good, but Joe D was among the top five to ever play the game.