DJ was a point guard not a shooting guard... not that he wouldn't do well at that position.
I'll admit that I went by the Wikipedia article, which I figured was written by someone more on top of the issue than most of this board. It claims that he played SG during his tenures with the Sonics and Suns, then PG with with Celtics. But looking at old Suns statistics, it appears that he was more of a hybrid; the team lacked a true PG and the offense was run through Adams as often as not.
Dennis Johnson never led the Suns in assists, which I generally consider to be one of the necessary characteristics of a true point guard.
By the way, this may be hard to believe for many long-time fans (including me!), but the 1980-81 Suns -- the infamous 57-25 team that bowed out ingloriously to Cotton Fitzsimmons's Kansas City Kings in the first round by losing Game 7 at home -- actually
led the league in defensive points per possession (
http://www.basketball-reference.com/teams/PHO/1981.html). Offensively, they were below average. The next two years' teams (after Truck Robinson was replaced by Maurice Lucas) also made defense their calling card,
and they slowed the pace down.
So the Suns, as it turns out, haven't always been run-and-gun. They've found ways to fall short as a defensive team as well. Something to chew on, perhaps.