Let's look more closely at the numbers during the height of the team's elite years and focus on the contribution that Russ made to the rushing stats.
In 2012, the team averaged 160 yd/game (3rd overall). Russ averaged 30 yd/game. Without Russ, the delta = 130 yd/game.
In 2013, the team averaged 135 yd/game (4th overall). Russ averaged 35 of those. Delta = 100 yd/game.
In 2014, the team averaged 170 yd/game (1st overall). Russ accounted for 55 of those. Delta = 115 yd/game.
In 2015, the team averaged 140 yd/game (3rd overall). Russ, 35 of those. Delta = 105 yd/game.
Without Russ' contribution, the team's rushing average/game would be more the average of the league, ranking the team more in the #14 to #18 overall instead of in the Top 5.
Hoping for 150 yd/game without the benefit of a running QB is fairly unrealistic. Not saying it can't happen just that it's a stretch.