"Shanahanigans" was without a doubt one of the most knee-jerk reactions in fantasy football and the surprising thing is that it stuck. I say this b/c Shanahan's RBs have endured some of the most ridiculous set of circumstances the past 5-6 years yet everyone ignores it.
2007: 1st year in a while that Shanahan hadn't produced a 1,000 yard rusher. I believe injuries or possibly a drug related type of suspension for Travis Henry?
2008: Shanahan's last year in Denver. Shanahan couldn't keep an RB healthy to save his life. The Travis Henry suspension might have come here. Either way, Shanny must have had 6 RBs who had between 30-70 carries and all of them fell to injury at one time or another.
2 Year Hiatus...
2010: Torain was getting workhorse type of carries on his way to 1,000 yards and...you guessed it, another injury derailed that.
2011: Drafts Helu, Royster, and trades for Hightower. That to me comes across as a "#### this, I'm fixing this problem once and for all" type of offseason. Most talented stable he's had in years. Hightower gets workhorse carries early in the year and was touted by many as one of the biggest steals of the fantasy season and then....he gets injured. Later in the season Helu gets workhorse carries, starts putting up monster numbers and...you guessed it again, he gets injured. Royster then finishes the year on a high note, making the most out of his workhorse carries.
2012: Hightower still recovering from ACL, Helu has whatever the hell he has in both of his achilles so Shanny gives the nod to Royster b/c of how he finished 2011 and surprise...he gets sidelined by a knee injury. Enter Alfred Morris.
As for what that means for Helu, Rosyer, and Morris....
Shanny just wants an RB to step up, stay healthy, and not make mistakes. He doesn't need a superstar (see Clinton Portis trade). Not sure who will step up but I wouldn't be surprised if Helu is in the "doghouse" despite his huge game in Week 4. He fumbled a toss play then kicked the ball out of bounds (even though it was negated by a penalty, Shanahan still saw it). Consequently, Helu didn't see touches until late in the game. Once he finally got back into the game, Helu had some great runs, but still made a couple mistakes. Most notably he didn't run out of bounds late in a two minute drill, which resulted in him losing his shoe when he got tackled in bounds. Helu stood there like a deer in headlights looking to the sideline, as if wanting to be spelled b/c he couldn't put his shoe back on (due to heavy padding on his foot for his Achilles injury). This shoe thing lasted for 2 or 3 plays, it was ridiculous.
While you guys have them rated by skill set, I'm ranking them in the order which they'll receive their chance to shine:
Morris/Royster/Helu