Army placement is extremely important. What I dislike about SC2 is there's no real reason for non-deathball centric play, i.e. not splitting your army up. Sure, you might harass with some drops, but you simply need your army clumped up to fight their clumped up army.
Obviously it isn't as black and white as that (you have to consider storms and such in TvP, widow mines in ZvT, etc.) but when you have a battle it's usually just at one place on the map. That being said, seeing a zerg completely surround a terran army from all flanks is sick
