Right now they essentially need to do it again. They have a decent team...its not bad, but its certainly not a quality finals outfit, even at full strength
This is the crux of the argument - if there was a team as good as Hawthorn 12-16 (Geelong 07-11, etc) then they would - but the simple answer is no-one is that good anymore.
But for suffering multiple in-game injuries, Hawthorn could well have another two wins and be sitting comfortably in the top 4 (they did, and they don't) - with the prospect of their #1 player being available late in the year. For a potential top-4 side to add a quality player of the ilk of Mitchell - they would have to consider themselves a flag contender.
Are other teams better? Yes, clearly. Other teams have more depth too. But it's not completely out of the question that Hawthorn could have some luck with injury, finish in the lower parts of the top-8 and from there who knows. They certainly have the coaching staff to do it.