If you treat the word anarchism as "anarcho-communism", then you are right.
Even from historical perspective, individual anarchism is almost as old, as communitarian.
"Anarcho"-capitalists claim to be anarchists because they say that they oppose government. As such, as noted in the last section, they use a dictionary definition of anarchism. However, this fails to appreciate that anarchism is a political theory, not a dictionary definition
By the way anarcho-capitalism is compatible top down with other form of more strict anarchism. You can make a voluntary anarcho-communistic society inside anarcho-capitalistic society.