I am sure there are many players in the Passing Game that are over looked.
But I have some issues with the Passing Game. Like WIDE OPEN players never being looked at until the play sinks like the H.M.S. Titanic.
Also, this involves a really good QB (ironically enough, of which I have). Those cost and don't grow on trees. And then even a really good QB can play really poorly (mine has) due to a variety of factors from OL to Targets (WR/TE) to Play Book.
For a Running Game, theoretically you need a Running Back, then 5 OL and a TE that focus on STR and Run Block. That's... well, pretty much it. And Discipline, because a Holding Call or False Start is going to kill your drive 90% of the time it happens. So that's very important as well.
I'm not sure how important WR Blocking is to the Running Game, hard to gauge since they are off screen and you can't really watch the engages... but it's simply enough to find OL/TE to move to WR, and there are a SURPRSING number of WR with amazing STR/RB. Now, they likely **** at things like SPD/ACC/Catch... but we aren't sending them out to catch, so what do we care. We just want that STR/Run Block.
So while it is far from the only way, I think between Run and Pass that Run is the easier one to build. Between Run, Pass or Mix I feel Mixed will take the absolute most talent, and finding a team of really 'balanced' players would be very tough, while having Specialty types would hamper your build (Think the 100 STR/20 RB/80 PB LT next to the 100 STR/80 RB/20 PB LG... or how hard it might be to find a 100 STR/80 RB/80 PB at all 5 spots).
Now I get I'm taking a VERY simplistic view, I really do. But I think this may be the easiest way, and the quickest way to build the most effective team one can.