Runs and RBIs are at least to a certain extent dependent on where a guy bats in the order, and the strength of the offense he plays in. Guys will get runs when they're decent hitters and hopefully hit high in the order with good bats behind them (speed helps too). Guys will accrue RBIs when they're a decent hitter and hit behind a two or three other guys who can regularly get on base. I guess you could call both runs and RBIs context categories - you need to look at the team situation in order to figure them out. In both cases it's best to target guys in high powered offenses.
As a general rule of thumb you're looking at the 1 and 2 holes for runs, and the 3-5 holes for RBIs (and runs, to an extent). Guys hitting later in the order have less chances to accrue either stat, both because they're surrounded by (usually) weaker hitters, and also because the guys at the end of the order will get less ABs over the course of the season. That's the broad strokes anyway.