"Balance" simply meaning that they want to run the ball more. Last year, the Colts threw the ball on more than 60 percent of their plays, the Packers depended on Aaron Rodgers to provide more than 70 percent of their offense, and In the last day or so, a member from each team has talked in separate articles about the value of a consistent running game.
First, here is Rodgers talking to Milwaukee Journal Sentinel writer Tyler Dunne: "The ability to have a balance can give you those eight-man boxes and one-on-one matchups outside and open up some lanes for those guys. We usually win those one-on-one battles. ... I like our offense and I like what we can do in the passing game. And now, I think we can complement it with a more consistent running game with two stud backs we got in the draft (Eddie Lacy , Johnathan Franklin ) and a used-car salesman (DuJuan Harris )."
And here is Colts offensive coordinator Pep Hamilton talking to the Dan Pompei of the National Football Post: "You have to have balance in your offense. The teams I've been a part of where the quarterback has been effective and offensively we've had success consistently were the teams that were about to run the football."
These stories should mean good things for the likes of Ballard and Lacy, and yes, those two look like they could be decent fantasy RB2 players in 2013. But let's be real about this: While I don't question the Colts' desire to take some pressure off a still-young franchise quarterback, Ballard isn't an otherwise special player. Andrew Luck is what drives Indy's offense, and that should continue.
Similarly, it would be nice for the Packers to have a dependable ground attack to make their offense more complete. But if the Packers are going to force that at the expense of fewer passes from Rodgers, that would be plainly stupid.
In conclusion, don't put much into the quotes above. What the Colts and Packers want to improve now isn't going to lead them to compromising their existing offensive strengths.