We also improved defensively when Keith Downing was here, he specialised in out of possession play. That's certainly an area that needs sharpening.
I recall playing Wycombe and noting how nearly every attacking move seemed to be based on getting the ball wide and sending it into the box in a set piece style for knockdowns etc. It was typically Ainsworth but seemed to be based on their strengths at set pieces. Likewise, I've seen Wrexham employ a similar strategy on occasion.
Set piece or fuid, if you've developed a set piece routine that's well drilled, it must bring benefits, even if adapted for open play use. It certainly worked for Bristol City.