While the role of Europeans in exacerbating existing tensions shouldn’t be overlooked, it’s incorrect to call the division between Hutus and Tutsis “artificial.” Tutsi were originally a herding class, and Hutus were farmers. Divisions and conflicts between such groups run deep throughout history in many locations. Eventually Tutsis became feudal overlords, and imposed practices such as a system of indentured labor that had to be provided by Hutus. The distinction was sufficiently developed that Hutu women were prohibited from marrying Tutsi men (presumably to control inheritance): https://en.wikipedia.org/wiki/Ubuhake.

It’s like when people say that the British created the tensions between Muslims and Hindus on the subcontinent. That overlooks the millennia of Muslim invasions and rule by sultanates (the process by which I came to have an Arabic surname despite being born 8,000 miles from the Middle East).