If I recall correctly, GI RB's attack their side of the field. ie. RB/R runs to the right side of the field, RB/L runs to the left side of the field, RB/C runs up the middle. Any spot left over is taken up by the RB closest to the spot, or split if it's equal. Example, if you have RB/C and RB/L, then the RB/C will take all carries up the middle and to the right. If you have RB/L and RB/R, then runs up the middle will be split (somewhat evenly, but not always) between the two RB's.
Now, RB's overrun FB's. If you have a RB lined up in the same position as a FB, the FB will get NO carries. If they are split (FB/C and RB/R) I think that FB will get the runs up the middle and RB gets all others. I'm not positive on this aspect, but my experience has shown that if you have a FB and a RB, the FB's carries are very limited or non-existant.


As to whether or not to have two RB's? I use two RB's currently. I've noticed that some games 1 RB does well, while the other will stink it up. Other games it's the opposite. Still some games, both do extremely well and a very few games, both have stunk. With two RB's I almost always have at least 1 RB doing well and providing a strong running game. It's probably my RB's low consistency that is causing the variation. If you have a high consistency RB, a 1 RB setup might work well.

good choice..
at first, the running game is much easier to get going. there's a lot of factors that go into a successfull passing attack. you'll get there with some training. but for now, i think a good running attack is the best way to go for your team