Honor them with backstory
Batwing #4 takes a bit of a break from the ongoing story with Massacre with the exception of a few opening pages to instead focus on David's backstory. While the telling of David's history is enjoyable enough on its own, it's disappointingly short with details, and the terrible things within David's past are mostly just talked about, not shown. It feels as though the backstory would have been handled better if we had seen glimpses of David's past interweaved throughout the previous issues as oppose to saving issue four to talk about them at length. In short, David's past doesn't feel as developed as it should be. It's a disappointing turn of events since unlike Batman, David/Batwing has killed before, and playing up this fact a bit to create a bit of inner turmoil for David really would have been a good first step towards getting Batwing from out from under Batman's shadow.
Batwing 4 ends with the writers gearing you up for the continuation of the present day story line, but aside from a dropped line or two in David's backstory, you don't really feel much of an immediate connection between the events of the past and what is happening present day. Subplots from previous issues such as the history of The Kingdom don't show up at all, and the lack of a building conflict really makes this issue feel more like filler than anything else.