I think Rowen got caught in the changes - i.e. (a) his background was as an O-line coach, (b) his key mission was to fix the running game, (c) then the Cards (appropriately) added Warner and Fitz to the offense and decided to "go airborne" perhaps a bit earlier than anticipated and then (d) (again appropriately) added Edge James, and along with him, the stretch-play/zone blocking approach to the running game.
He became the wrong guy for the wrong job.
Regarding more aggressive play calling, I think a key watchword should be "unpredictability." For awhile, I've been intrigued by the Mike Martz approach to play calling (one that would appear to be in synch with what Dennis is looking for). Martz's team could be 3rd and a foot on his own 10 yard line, and he'd dial up a skinny post or deep sideline pattern. Or he could be 3rd & 25 at midfield, and he'd call a draw play. (He just didn't care).
I'd be tempted, on every offensive down, to favor Kruczek pulling a slip of paper from a hat with a play on it, and let the chips fall where they may.
I also am optimistic about the anticipated move to more of a downhill approach to the running game - at least until we can get guys who can block effectively on stretch plays.
At this point in the season, the objective should be not be about "process" (i.e. learning how to zone block) but "results" - (i.e. gaining freakin' yardage).