You are right. Too many in the West are quick to simply label him as a savage when in reality he was the best combination of bad ass and intellect that ever lived. He also had a knack for picking out others who shared his same leadership abilities. (e.g. Generals like Subedai).
One of the things I recall from the book is how he would pull up his army outside the walls of each city he arrived at.
A message would be sent forth, affixed to an arrow, spear, some sort of projectile, informing the inhabitants that they must immediately pay Genghis a substantial tribute, in gold and other valuables, and also a substantial tax from this day forward, which would guarantee them his allegiance and protection.
The cities would usually send some poor messenger out with a missive that said, Sorry, we’re not going to pay you anything, but you are welcome to come in for coffee and pie.
The Mongols would then affix a note to the messenger and catapult HIM inside the walls, the note reading: Prepare All To Die.