[MrForbes]

If you look at the relationship of CG relative to where the wheels contact the floor, and then you look at the forces acting on the robot going around a turn at speed, you might find that locating the CG over towards one side will indeed affect the speed at which you can make a corner bofore the robot falls over. Although if your CG is low enough, then you will loose traction long before this becomes an issue!

24" sounds way way too tall for a robot with no ball handling stuff, I'd shoot for 8" or less overall height, not counting flag holder.