Edmonton ... in the most literal sense ... has exactly:
Three top-2 centers and fifteen bottom-6 wingers with nothing in between.
One top-4 defense and nine bottom-pair defense with nothing in between.
Zero starting goalies and two backup goalies with nothing in between.
Fair enough point with the forwards, though I'd point out that at least a few of those bottom 6 guys are more better described as top 9, meaning they optimally are third line guys but can play up in the lineup if need be. They have a few young forwards who could make the move into that description or better too, but realistically they are probably a year or two away from doing that.
Your rating of their backend is simply wrong. They have three top 4 dmen in nurse, klefbom, and larsson. Russel and Benning both are capable bottom pair guys, though I wouldn't mind seeing Benning bumped down into a number 7 role if a couple of the younger dmen can step up. They have about 5 young dmen that will all be competing for two spots in that roster, so there's a good chance they end up with two solid options.
Goaltending is tough to judge. It really depends on how well the team in front of them performs. Koskinen showed he has what it takes to be a good goalie in this league, wether that be +/- 40 games will depend on how well Smith performs. This is basically a tandem setup that isn't much different from what they had last season. So again, it will depend largely on their team play in front of these guys.
As far as the team goes: the kind of players they've been brining in, along with additions from their farm system, fit nicely with their new head coaches style of coaching. He had success in Arizona with lineups that depended on the hard work of role players and everybody doing their part.
But ya, they are still missing 1-2 good forwards and 1 top 4-2 dman from being a contender. Likely won't find the forwards within this season, but may find another top 4 dman out of that bunch of young players they have. The good thing for them though is that they're division is all over the place right now and, with maybe the exception of Calgary, it's anybodies guess who'll be in the top 3 this season.