I agree with most people wanting different depth charts for each formation, I also have really disliked the 50/50 split 60/40 ect. I preferred it much more when I could give each running back a number that proportionalized their touches relevant to one another, as I usually keep 6-8 RB on my roster I would like to be able to get carries to more guys than my #1 and #2 RB with a really uncontrolled number of touches for your fullback. I know changes to make it not as easy to run in one of the last major updates, however I feel that ease of control of touches was lost more than anything. When you used to be able to break it up so #1 got 40% #2 got 20% #3 got 20% #4 got 10% and #5 got 10% of the total touches, it was much easier to develop multiple RB when you carry about 8 at any given time.
Also, would like some sort of logic implemented like a benching, say if one particular RB carried it 10 times for 22 yards and RB # 2 carried it 6 times and has 45 yards. In real life #2 is gonna continue to get the carries that game until he screws up or is no longer effective. This could be accomplished at not only RB but at every position based on opportunities and successes vs failures weather it be a QB pass or a LB chance at a tackle. This however could become tricky in the sense that if your best DB is getting burned by a all-American WR, you don't want your worst DB coming in for him. Defense may be a little harder or even uncalled for, I mainly bring this up because I'm tired of having two very closely skilled players at QB, set them to 90% fresh pull (in hopes of figuring out who to go with in the second half, based on preformance) and have the starter go 3-14 while the back up who is very equal skill wise only gets 3-4 in opportunities. It would have to be in the form of an option for each position in the case that your starter is head and shoulders better than your backup as what qualifies for what's "bad performance" however I think that it would make things a loads more realistic.
Sorry for any grammar errors, most likely auto correct on this phone. More ideas to come once I get to a computer