What was unorthodox about US military tactics in Iraq?

What were the unorthodox tactics and why were they unorthodox? I’ve read that the use of armored formations to assault the city was a novel approach but how so? Can a military mind give me a brief rundown?

This article might be of interest

And IANAMMBIPALOVG*, but I believe traditional military thinking is that you have to use ground troops to assault a city and root out the enemy fighters that are presumably inside. Tanks tend to be–or used to be–extremely vulnerable in cities, because any idiot with an RPG or other anti-tank weapon can pop out of the rubble and take a shot.

  • I Am Not A Military Mind But I Play A Lot Of Video Games, which is probably not relevant at all.

We also didn’t try to reduce the cities to rubble before entering them. Conventional US wisdom is to bomb everything completely flat before sending in ground troops.