The best headers of the ball are around 5' 11 to 6' 2. That height is optimum because your tall but your height doesn't hinder your swiftness in manipulating your leap and contact with the ball.
Ronaldo, Lewandowski, Cavani, Falcao, Ramos, etc get many headed goals because of that.
Also another very important thing people miss out is winning duels in the middle of the park is very different to being an aerial goal threat.
Tall players win aerial duels in the middle of the pitch but can't manipulate their bodies well enough to score headers consistently when the ball doesn't have much air time.
These people need lobbed up balls so they can use their height to their advantage.
Also, Football purists ignore how important it is for strikers and defenders to be great in the air. You can't always play with ball to your feet. I don't consider a striker/CB complete if he's not dominant in the air. Period.