Hey! It is me, the one that thinks he is so good at games... One thing i would like to share with you is my wastage rule of thumb. You see, when you are playing a game like "Star Craft" with units, you lose damage by packing it into one unit. You see, one unit can only deliver one attack each attach round, so, it makes sense to spread your damage a lot!
Look at it this way;
A zealot fighting four zerglings, they will deal five damage each attack, and, the zealot will take three shots to eliminate each zergling, or so. This means, three time four equal twelve attacks to eliminate all the zerglings, and the zerglings have to deal one hundred plus one hundred damage, yes? Thing is, once the one zerg is eliminated, there are still three attacks a round coming in! That means, with advanced tactics, you could bring a zergling out f combat that the zealot is attacking, making the other three hit them in the back, as the zealot loses an attack to chase the unit, yes?
* Tip, use your guard function!
So, it makes less sense to have fewer units. On the other hand, if you have three zealots, you could eliminate a zergling every round, which would make sense, but, with the swarm of the zerg, this mean they will make you change targets and they will heal a meager amount, where you now need to deal them four attacks! Makes sense to avoid power units, yes?