That's the trick, figuring out if going more offencive or more defencive is more benificial. If u expand quickly, u leave points vonerable to attack, might make the other combatant too defencive, not probing for weakness. But i suppose if u could micro manage, and u met up with an opponent like that, u'd try to move forces around, and find that sweet spot, effectivly stoping his advance, making him backtrack, putting him on the defencive.