“These features cannot be organised into a system; many of them contradict each other and are also typical of other kinds of despotism or fanaticism. But it is enough that one of them be present to allow fascism to coagulate around it.” Umberto Eco is a smart guy but that essay is pretty silly. Fascism: anywhere, everywhere, and you can tell it's coming by any number of contradictory and non-definite phenomena.
If I were to try to grasp fascism from a different angle and how it relates to other totalitarian tendencies I would characterize it by the social class that puts it into power. The middle class has been the historical base of power for fascism. The points Eco makes are quite resonant amongst middle class people in many countries in particular the downwardly mobile middle class who feel like they are being cheated out of something they are entitled to. That is the mechanism by which fascism takes hold.
In contrast, Marxism-Leninism is primarily concerned with the proletariat and intelligentsia. Maoism is primarily concerned with the peasantry. Really, you can identify a political ideology without looking too closely at its details by examining how it goes about class struggle: its implementation as an actual political movement and not an abstract set of ideas.