Drafting Najee Harris makes the Steelers SuperBowl Contenders this season. No longer are they a one-dimensional offense with Najee Harris back there and he's a 3 down NFL caliber RB....day one starter. Exactly what they needed.
As for the O-line it's certainly needs improvement but I think Depth is lacking on the Steelers O-line. The starting O-line on paper doesn't look bad but lacks in game experience as a group that should improve as the season progresses. I know we lost Big Al, Feiler & Pouncey since last season but I don't feel Big Al & Feiler were a great loss and Hassenhauer played pretty good last season in Pouncey's absence. Okorafor, Dotson, Hassenhauer, DeCastro & Banner for a starting O-line I think Dotson & Banner are complete road graters in the running game. A few mid-round picks for some depth to bolster that O-line incase of injuries and I think they will be ok.
Let's not forget the Steelers also need CB as they lost, Nelson, Hilton & Justin Layne (might be in the dog house with recent events)
I think Steven Nelson is still floating around out there in Free Agency....maybe they can somehow get him back this season on a 1 year deal.