The Cowboys success in 2014 showed how valuable a dedication to the running game could be for a club in this pass happy era. The commitment made to the OL while having Romo and Dez makes RB a valuable position in Dallas. Thus elite talent at the position should be valued due to the difference it made in 2014.
Elliott would be an impact player in Dallas the minute he steps off the plane. That can't be denied...can it? Not sure they pull the trigger at #4 and I am on record saying that IF they evaluate a QB as a franchise QB and he is on the board at #4...take him. BUT...if they see the guys as overvalued due to their position and think they aren't franchise guys...walk away. Just look at the crop of QB's in the 2017 draft....one or more will likely be 1st rounders and based on what I've seen as of today....none are franchise QB's but they will be overdrafted and overvalued just because they are a QB.
Regarding the RB position, I can see a shift to teams taking RB's in Round 1 use them up for 5 years then repeating the cycle. It may start as early as 2017. There could be...I repeat "could be", 6 RB's taken round 1 or early 2nd next year (Parine from Oklahoma; Freeman from Oregon; Cook from Florida St.; Chubb from Georgia; McCaffrey from Stanford; and Fournette from LSU). The League devalued the position briefly but saw the Seahawks be successful with the right RB and the 2014 Cowboys do the same so it won't last. Just look at how Guards and Centers are now seen as 1st round guys. GM's, coaches and scouts change views on position from time to time.