sure Hickey went #4 in 2007 (and was the consensus opinion at the time was that it was a gamble, ie mistake), so that's such a huge, huge anomaly that it's best considered to be a mistake and a reason why it won't happen again.
Almost all the d-men picked in draft years since then have pretty much gone in terms of form. 2008 Doughty, Bogosian, Pietrangelo; 2009 Hedman Ekman-Larsson, Cowen, Ellis; 2010 Gudbranson (but then Fowler and Gormley slipped behind McIllrath-- shame on the Rangers, everybody said so at the time); 2011 Larsson, Hamilton, Brodin, Siemans; 2012 R. Murray, then a whole string of d-men with #4 thru #9 and the hick-up being #4 Reinhart-- ("skating is everything" and don't get too focused on the "toy" on the closest shelf); 2013 Jones, Nurse, Ristolainen; 2014 only Fleury was a top 10 guy; and 2015 Hanifin, Provorov, Werenski. Not a lot of controversy in the order of these top 10 d-men picks in the last 9 entry drafts.
if one caveat may be mentioned in terms of Oiler's drafting of d-men, it is that they haven't selected enough d-men playing outside the CHL, that is Euro/ International/ American guys. They perhaps haven't valued the Euro/ International/ American player as highly as they might have. Klefblom was, if he gets healthy again, a good pick up. But, most of the cream players in terms of d-men have a stint playing in the CHL. Things are changing a bit in this regard with Hanifin and Werenski in 2015, Ristolainen in 2014, and maybe perhaps McAvoy is a good mid 1sr round pick this year.