For mine, you always draft based on quality, not need. But if there are players at our picks that are all about par on quality, then we pick from that pool based on need. And the priority needs to be outside run, followed by defensive talls.
Personally, I think the coaching staff have decided we stumbled onto a good full-forward in Bruce - originally a junior AA full-forward who the Giants had to reinvent into a backman. In fact, this makes him a bit like Delaney and Membrey: a good positional player hampered by other REALLY good players being locked into his position. But Bruce going forward means one less person down back. As such a tall like McDonald or Marchbank should be a priority.
But of far greater concern was our utterly terrible performance on the outside last year. In terms of clearances, often we weren't that bad. The problem wasn't our ins getting the ball, it was what we did with it once it got out. I think the good news of this draft is that there are bound to be some good sliders who are outside players. After all, there are about 7 or 8 "locks" in the top 20, such as Tracs, Macca, 2MP, Brayshaw, as well as FS and Academy players like Heeney and Moore. That leaves about 12 spots: you'd have to think one (or even two) of Cockatoo, Weller, Duggan, Langford, De Goey, Garlett would slide. Add to that the possibility of a tall defender like Marchbank, or even Goddard (although that's unlikely) sliding, and I think 21-22 could reap some nice rewards.